calendar.different_locale.__enter__ returns None, not _LocaleType (#7108)

stdlib/calendar.pyi

@@ -105,7 +105,7 @@ class HTMLCalendar(Calendar):
 
 class different_locale:
     def __init__(self, locale: _LocaleType) -> None: ...
-    def __enter__(self) -> _LocaleType: ...
+    def __enter__(self) -> None: ...
     def __exit__(self, *args: Any) -> None: ...
 
 class LocaleTextCalendar(TextCalendar):