[mod] addition of various type hints / tbc

- pyright configuration [1]_
- stub files: types-lxml [2]_
- addition of various type hints
- enable use of new type system features on older Python versions [3]_
- ``.tool-versions`` - set python to lowest version we support (3.10.18) [4]_:
  Older versions typically lack some typing features found in newer Python
  versions.  Therefore, for local type checking (before commit), it is necessary
  to use the older Python interpreter.

.. [1] https://docs.basedpyright.com/v1.20.0/configuration/config-files/
.. [2] https://pypi.org/project/types-lxml/
.. [3] https://typing-extensions.readthedocs.io/en/latest/#
.. [4] https://mise.jdx.dev/configuration.html#tool-versions

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>
Format: reST

searx/engines/duckduckgo.py

@@ -4,11 +4,8 @@ DuckDuckGo WEB
 ~~~~~~~~~~~~~~
 """
 
-from __future__ import annotations
-
 import json
 import re
-import typing
 
 from urllib.parse import quote_plus
 
@@ -31,13 +28,6 @@ from searx.enginelib import EngineCache
 from searx.exceptions import SearxEngineCaptchaException
 from searx.result_types import EngineResults
 
-if typing.TYPE_CHECKING:
-    import logging
-
-    logger: logging.Logger
-
-traits: EngineTraits
-
 about = {
     "website": 'https://lite.duckduckgo.com/lite/',
     "wikidata_id": 'Q12805',