[pre-commit.ci] auto fixes from pre-commit.com hooks

Author: pre-commit-ci[bot]

stdlib/argparse.pyi

@@ -124,6 +124,7 @@ class _ActionsContainer:
             argument_default: Any = ...,
             conflict_handler: str = ...,
         ) -> _ArgumentGroup: ...
+
     def add_mutually_exclusive_group(self, *, required: bool = False) -> _MutuallyExclusiveGroup: ...
     def _add_action(self, action: _ActionT) -> _ActionT: ...
     def _remove_action(self, action: Action) -> None: ...