set_lazy_imports_filter's importer arg can be None

Author: Avasam

stdlib/sys/__init__.pyi

@@ -10,7 +10,7 @@ from typing_extensions import LiteralString, deprecated
 
 _T = TypeVar("_T")
 _LazyImportMode: TypeAlias = Literal["normal", "all", "none"]
-_LazyImportFilter: TypeAlias = Callable[[str, str, tuple[str, ...] | None], bool]
+_LazyImportFilter: TypeAlias = Callable[[str | None, str, tuple[str, ...] | None], bool]
 
 # see https://github.com/python/typeshed/issues/8513#issue-1333671093 for the rationale behind this alias
 _ExitCode: TypeAlias = str | int | None