Use generator for contextmanager

Author: max-muoto

stdlib/contextlib.pyi

@@ -74,7 +74,7 @@ class _GeneratorContextManager(AbstractContextManager[_T_co, bool | None], Conte
             self, type: type[BaseException] | None, value: BaseException | None, traceback: TracebackType | None
         ) -> bool | None: ...
 
-def contextmanager(func: Callable[_P, Iterator[_T_co]]) -> Callable[_P, _GeneratorContextManager[_T_co]]: ...
+def contextmanager(func: Callable[_P, Generator[_T_co]]) -> Callable[_P, _GeneratorContextManager[_T_co]]: ...
 
 if sys.version_info >= (3, 10):
     _AF = TypeVar("_AF", bound=Callable[..., Awaitable[Any]])