[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/mullvad_leta.py

@@ -36,10 +36,8 @@ Implementations
 ===============
 
 """
+import typing as t
 
-from __future__ import annotations
-
-import typing
 from urllib.parse import urlencode
 import babel
 from httpx import Response
@@ -49,13 +47,6 @@ from searx.locales import get_official_locales, language_tag, region_tag
 from searx.utils import eval_xpath_list
 from searx.result_types import EngineResults, MainResult
 
-if typing.TYPE_CHECKING:
-    import logging
-
-    logger = logging.getLogger()
-
-traits: EngineTraits
-
 search_url = "https://leta.mullvad.net"
 
 # about
@@ -80,7 +71,7 @@ time_range_dict = {
     "year": "y",
 }
 
-LetaEnginesType = typing.Literal["google", "brave"]
+LetaEnginesType = t.Literal["google", "brave"]
 """Engine types supported by mullvadleta."""
 
 leta_engine: LetaEnginesType = "google"
@@ -88,12 +79,12 @@ leta_engine: LetaEnginesType = "google"
 
 
 def init(_):
-    l = typing.get_args(LetaEnginesType)
+    l = t.get_args(LetaEnginesType)
     if leta_engine not in l:
         raise ValueError(f"leta_engine '{leta_engine}' is invalid, use one of {', '.join(l)}")
 
 
-class DataNodeQueryMetaDataIndices(typing.TypedDict):
+class DataNodeQueryMetaDataIndices(t.TypedDict):
     """Indices into query metadata."""
 
     success: int
@@ -112,7 +103,7 @@ class DataNodeQueryMetaDataIndices(typing.TypedDict):
     previous: int
 
 
-class DataNodeResultIndices(typing.TypedDict):
+class DataNodeResultIndices(t.TypedDict):
     """Indices into query resultsdata."""
 
     link: int