Remove accidental change in RawQuerySet.

Author: syastrov

django-stubs/db/models/query.pyi

@@ -159,7 +159,7 @@ class RawQuerySet(Iterable[_T], Sized):
     @overload
     def __getitem__(self, k: str) -> Any: ...
     @overload
-    def __getitem__(self, k: slice) -> QuerySet[_T, _Row]: ...
+    def __getitem__(self, k: slice) -> RawQuerySet[_T]: ...
     @property
     def columns(self) -> List[str]: ...
     @property