[fix] pyright repported errors

The errors make pyright usage useless since a new error won't be seen [1].

[1] https://github.com/searxng/searxng/pull/1569

```
  searx/compat.py:11:27 - error: Expression of type "Type[cached_property[_T@cached_property]]" cannot be assigned to declared type "Type[cached_property]"
    "Type[cached_property[_T@cached_property]]" is incompatible with "Type[cached_property]"
    Type "Type[cached_property[_T@cached_property]]" cannot be assigned to type "Type[cached_property]" (reportGeneralTypeIssues)
  searx/utils.py:69:36 - error: Expression of type "None" cannot be assigned to parameter of type "str"
    Type "None" cannot be assigned to type "str" (reportGeneralTypeIssues)
  searx/utils.py:573:85 - error: Expression of type "None" cannot be assigned to parameter of type "int"
    Type "None" cannot be assigned to type "int" (reportGeneralTypeIssues)
  searx/webapp.py:1306:22 - error: Argument of type "str" cannot be assigned to parameter "__a" of type "BytesPath" in function "join"
    Type "str" cannot be assigned to type "BytesPath"
      "str" is incompatible with "bytes"
      "str" is incompatible with protocol "PathLike[bytes]"
        "__fspath__" is not present (reportGeneralTypeIssues)
  searx/webapp.py:1306:68 - error: Argument of type "Literal['themes']" cannot be assigned to parameter "paths" of type "BytesPath" in function "join"
    Type "Literal['themes']" cannot be assigned to type "BytesPath"
      "Literal['themes']" is incompatible with "bytes"
      "Literal['themes']" is incompatible with protocol "PathLike[bytes]"
        "__fspath__" is not present (reportGeneralTypeIssues)
  searx/webapp.py:1306:78 - error: Argument of type "str | Any | None" cannot be assigned to parameter "paths" of type "BytesPath" in function "join"
    Type "str | Any | None" cannot be assigned to type "BytesPath"
      Type "str" cannot be assigned to type "BytesPath"
        "str" is incompatible with "bytes"
        "str" is incompatible with protocol "PathLike[bytes]"
          "__fspath__" is not present (reportGeneralTypeIssues)
  searx/webapp.py:1306:85 - error: Argument of type "Literal['img']" cannot be assigned to parameter "paths" of type "BytesPath" in function "join"
    Type "Literal['img']" cannot be assigned to type "BytesPath"
      "Literal['img']" is incompatible with "bytes"
      "Literal['img']" is incompatible with protocol "PathLike[bytes]"
        "__fspath__" is not present (reportGeneralTypeIssues)
  searx/engines/mongodb.py:8:6 - warning: Import "pymongo" could not be resolved (reportMissingImports)
  searx/engines/mysql_server.py:9:8 - warning: Import "mysql.connector" could not be resolved (reportMissingImports)
  searx/engines/postgresql.py:9:8 - warning: Import "psycopg2" could not be resolved from source (reportMissingModuleSource)
  searx/engines/xpath.py:187:28 - warning: "categories" is not defined (reportUndefinedVariable)
  searx/search/__init__.py:184:82 - warning: "flask" is not defined (reportUndefinedVariable)
  searx/search/checker/background.py:19:26 - error: Type of "schedule" is partially unknown
    Type of "schedule" is "(delay: Any, func: Any, *args: Any) -> Literal[True]" (reportUnknownVariableType)
  searx/shared/__init__.py:8:12 - warning: Import "uwsgi" could not be resolved (reportMissingImports)
  searx/shared/shared_uwsgi.py:5:8 - warning: Import "uwsgi" could not be resolved (reportMissingImports)
```

11 files changed, 22 insertions, 13 deletions

diff --git a/searx/compat.py b/searx/compat.py
index 504df7da..15e27d45 100644
--- a/searx/compat.py
+++ b/searx/compat.py
@@ -7,8 +7,11 @@
 # pylint: disable=C,R
 
 
+__all__ = ('cached_property',)
+
+
 try:
-    from functools import cached_property  # pylint: disable=unused-import
+    from functools import cached_property  # type: ignore
 
 except ImportError:
 
diff --git a/searx/engines/mongodb.py b/searx/engines/mongodb.py
index c833ca9e..63452bb6 100644
--- a/searx/engines/mongodb.py
+++ b/searx/engines/mongodb.py
@@ -5,7 +5,7 @@
 """
 
 import re
-from pymongo import MongoClient  # pylint: disable=import-error
+from pymongo import MongoClient  # pyright: ignore # pylint: disable=import-error
 
 engine_type = 'offline'
 
diff --git a/searx/engines/mysql_server.py b/searx/engines/mysql_server.py
index c16093fb..8d0a4956 100644
--- a/searx/engines/mysql_server.py
+++ b/searx/engines/mysql_server.py
@@ -6,7 +6,7 @@
 
 # import error is ignored because the admin has to install mysql manually to use
 # the engine
-import mysql.connector  # pylint: disable=import-error
+import mysql.connector  # pyright: ignore # pylint: disable=import-error
 
 engine_type = 'offline'
 auth_plugin = 'caching_sha2_password'
diff --git a/searx/engines/postgresql.py b/searx/engines/postgresql.py
index d8bbabe2..d7ff6a11 100644
--- a/searx/engines/postgresql.py
+++ b/searx/engines/postgresql.py
@@ -6,7 +6,7 @@
 
 # import error is ignored because the admin has to install mysql manually to use
 # the engine
-import psycopg2  # pylint: disable=import-error
+import psycopg2  # pyright: ignore # pylint: disable=import-error
 
 engine_type = 'offline'
 host = "127.0.0.1"
diff --git a/searx/search/__init__.py b/searx/search/__init__.py
index c517814d..9d337916 100644
--- a/searx/search/__init__.py
+++ b/searx/search/__init__.py
@@ -2,11 +2,12 @@
 # lint: pylint
 # pylint: disable=missing-module-docstring, too-few-public-methods
 
-import typing
 import threading
 from timeit import default_timer
 from uuid import uuid4
 
+import flask
+
 from searx import settings
 from searx.answerers import ask
 from searx.external_bang import get_bang_url
@@ -181,7 +182,7 @@ class SearchWithPlugins(Search):
 
     __slots__ = 'ordered_plugin_list', 'request'
 
-    def __init__(self, search_query: SearchQuery, ordered_plugin_list, request: "flask.Request"):
+    def __init__(self, search_query: SearchQuery, ordered_plugin_list, request: flask.Request):
         super().__init__(search_query)
         self.ordered_plugin_list = ordered_plugin_list
         self.result_container.on_result = self._on_result
diff --git a/searx/search/checker/background.py b/searx/search/checker/background.py
index f47e7d75..f8dfed4f 100644
--- a/searx/search/checker/background.py
+++ b/searx/search/checker/background.py
@@ -16,7 +16,7 @@ from searx import logger, settings, searx_debug
 from searx.exceptions import SearxSettingsException
 from searx.search.processors import PROCESSORS
 from searx.search.checker import Checker
-from searx.shared import schedule, storage
+from searx.shared import schedule, storage  # pyright: ignore
 
 
 CHECKER_RESULT = 'CHECKER_RESULT'
diff --git a/searx/shared/__init__.py b/searx/shared/__init__.py
index 98c9a11c..f03679c6 100644
--- a/searx/shared/__init__.py
+++ b/searx/shared/__init__.py
@@ -1,11 +1,14 @@
 # SPDX-License-Identifier: AGPL-3.0-or-later
 
 import logging
+import importlib
 
 logger = logging.getLogger('searx.shared')
 
+__all__ = ['SharedDict', 'schedule']
+
 try:
-    import uwsgi
+    uwsgi = importlib.import_module('uwsgi')
 except:
     # no uwsgi
     from .shared_simple import SimpleSharedDict as SharedDict, schedule
diff --git a/searx/shared/shared_uwsgi.py b/searx/shared/shared_uwsgi.py
index 4a6b0a15..0248c623 100644
--- a/searx/shared/shared_uwsgi.py
+++ b/searx/shared/shared_uwsgi.py
@@ -2,7 +2,7 @@
 
 import time
 from typing import Optional
-import uwsgi  # pylint: disable=E0401
+import uwsgi  # pyright: ignore # pylint: disable=E0401
 from . import shared_abstract
 
 
diff --git a/searx/utils.py b/searx/utils.py
index 15f4d709..4910b1b8 100644
--- a/searx/utils.py
+++ b/searx/utils.py
@@ -66,7 +66,7 @@ def searx_useragent() -> str:
     ).strip()
 
 
-def gen_useragent(os_string: str = None) -> str:
+def gen_useragent(os_string: Optional[str] = None) -> str:
     """Return a random browser User Agent
 
     See searx/data/useragents.json
@@ -570,7 +570,7 @@ def eval_xpath(element: ElementBase, xpath_spec: XPathSpecType):
         raise SearxEngineXPathException(xpath_spec, arg) from e
 
 
-def eval_xpath_list(element: ElementBase, xpath_spec: XPathSpecType, min_len: int = None):
+def eval_xpath_list(element: ElementBase, xpath_spec: XPathSpecType, min_len: Optional[int] = None):
     """Same as eval_xpath, check if the result is a list
 
     Args:
diff --git a/searx/version.py b/searx/version.py
index ec72062e..cefdb7a4 100644
--- a/searx/version.py
+++ b/searx/version.py
@@ -6,6 +6,7 @@ import os
 import shlex
 import subprocess
 import logging
+import importlib
 
 # fallback values
 # if there is searx.version_frozen module, and it is not possible to get the git tag
@@ -73,7 +74,8 @@ def get_git_version():
 
 
 try:
-    from searx.version_frozen import VERSION_STRING, VERSION_TAG, GIT_URL, GIT_BRANCH
+    vf = importlib.import_module('searx.version_frozen')
+    VERSION_STRING, VERSION_TAG, GIT_URL, GIT_BRANCH = vf.VERSION_STRING, vf.VERSION_TAG, vf.GIT_URL, vf.GIT_BRANCH
 except ImportError:
     try:
         try:
diff --git a/searx/webapp.py b/searx/webapp.py
index 151eb5cc..83bbeac0 100755
--- a/searx/webapp.py
+++ b/searx/webapp.py
@@ -1303,7 +1303,7 @@ def opensearch():
 def favicon():
     theme = request.preferences.get_value("theme")
     return send_from_directory(
-        os.path.join(app.root_path, settings['ui']['static_path'], 'themes', theme, 'img'),
+        os.path.join(app.root_path, settings['ui']['static_path'], 'themes', theme, 'img'),  # pyright: ignore
         'favicon.png',
         mimetype='image/vnd.microsoft.icon',
     )