Improve the definition of os._ScandirIterator (python#13013)

stdlib/os/__init__.pyi

@@ -22,7 +22,6 @@ from _typeshed import (
 from abc import abstractmethod
 from builtins import OSError
 from collections.abc import Callable, Iterable, Iterator, Mapping, MutableMapping, Sequence
-from contextlib import AbstractContextManager
 from io import BufferedRandom, BufferedReader, BufferedWriter, FileIO, TextIOWrapper
 from subprocess import Popen
 from types import TracebackType
@@ -794,9 +793,12 @@ def replace(
     src: StrOrBytesPath, dst: StrOrBytesPath, *, src_dir_fd: int | None = None, dst_dir_fd: int | None = None
 ) -> None: ...
 def rmdir(path: StrOrBytesPath, *, dir_fd: int | None = None) -> None: ...
-
-class _ScandirIterator(Iterator[DirEntry[AnyStr]], AbstractContextManager[_ScandirIterator[AnyStr], None]):
+@final
+class _ScandirIterator(Generic[AnyStr]):
+    def __del__(self) -> None: ...
+    def __iter__(self) -> Self: ...
     def __next__(self) -> DirEntry[AnyStr]: ...
+    def __enter__(self) -> Self: ...
     def __exit__(self, *args: Unused) -> None: ...
     def close(self) -> None: ...