Make qt.machinery.Unavailable inherit ModuleNotFoundError

With pytest 8.2, pytest.importorskip(...) now only considers ModuleNotFoundError
rather than all ImportErrors, and warns otherwise:
pytest-dev/pytest#12220

While we could override this via

    pytest.importorskip(..., exc_type=machinery.Unavailable)

this is a simpler solution, and it also makes more sense semantically:

We only raise Unavailable when an import is being done that would otherwise
result in a ModuleNotFoundError anyways (e.g. trying to import QtWebKit on Qt
6).

qutebrowser/qt/machinery.py

@@ -48,7 +48,7 @@ class Error(Exception):
     """Base class for all exceptions in this module."""
 
 
-class Unavailable(Error, ImportError):
+class Unavailable(Error, ModuleNotFoundError):
 
     """Raised when a module is unavailable with the given wrapper."""
 

tests/unit/test_qt_machinery.py

@@ -9,7 +9,7 @@
 import html
 import argparse
 import typing
-from typing import Any, Optional, List, Dict, Union
+from typing import Any, Optional, List, Dict, Union, Type
 import dataclasses
 
 import pytest
@@ -45,14 +45,14 @@ def undo_init(monkeypatch: pytest.MonkeyPatch) -> None:
 
 
 @pytest.mark.parametrize(
-    "exception",
+    "exception, base",
     [
-        machinery.Unavailable(),
-        machinery.NoWrapperAvailableError(machinery.SelectionInfo()),
+        (machinery.Unavailable(), ModuleNotFoundError),
+        (machinery.NoWrapperAvailableError(machinery.SelectionInfo()), ImportError),
     ],
 )
-def test_importerror_exceptions(exception: Exception):
-    with pytest.raises(ImportError):
+def test_importerror_exceptions(exception: Exception, base: Type[Exception]):
+    with pytest.raises(base):
         raise exception