fix(typing): Guard typing_extensions import in test fixtures

Ensures the typing_extensions import in test fixture _types.py is
properly guarded to avoid runtime ImportError when typing_extensions
is not available.

Author: tony

tests/fixtures/pluginsystem/partials/_types.py

@@ -12,7 +12,18 @@
 
 from __future__ import annotations
 
-from typing_extensions import NotRequired, TypedDict
+import typing as t
+
+if t.TYPE_CHECKING:
+    from typing_extensions import NotRequired, TypedDict
+else:
+    # Fallback for runtime, though this module should not be imported at runtime
+    try:
+        from typing_extensions import NotRequired, TypedDict
+    except ImportError:
+        # Create dummy classes for runtime
+        NotRequired = t.Any  # type: ignore[misc, assignment]
+        TypedDict = type  # type: ignore[assignment, misc]
 
 
 class PluginTestConfigSchema(TypedDict):