Stop lying about the metaclass

Author: AlexWaygood

stdlib/asyncio/unix_events.pyi

@@ -1,7 +1,7 @@
 import sys
 import types
 from _typeshed import Self
-from abc import ABCMeta, abstractmethod
+from abc import abstractmethod
 from socket import socket
 from typing import Any, Callable
 from typing_extensions import Literal
@@ -57,7 +57,7 @@ if sys.platform != "win32":
     else:
         __all__ = ["SelectorEventLoop", "AbstractChildWatcher", "SafeChildWatcher", "FastChildWatcher", "DefaultEventLoopPolicy"]
 
-    class BaseChildWatcher(AbstractChildWatcher, metaclass=ABCMeta):
+    class BaseChildWatcher(AbstractChildWatcher):
         def __init__(self) -> None: ...
         def close(self) -> None: ...
         if sys.version_info >= (3, 8):