Upgrade black version (#7089)

stdlib/asyncio/locks.pyi

@@ -21,6 +21,7 @@ else:
         def __init__(self, lock: Lock | Semaphore) -> None: ...
         def __enter__(self) -> object: ...
         def __exit__(self, *args: Any) -> None: ...
+
     class _ContextManagerMixin:
         def __init__(self, lock: Lock | Semaphore) -> None: ...
         # Apparently this exists to *prohibit* use as a context manager.