Add object.__subclasshook__ (#9755)

stdlib/builtins.pyi

@@ -110,6 +110,8 @@ class object:
 
     def __dir__(self) -> Iterable[str]: ...
     def __init_subclass__(cls) -> None: ...
+    @classmethod
+    def __subclasshook__(cls, __subclass: type) -> bool: ...
 
 class staticmethod(Generic[_R_co]):
     @property