Never explicitly inherit from object in Python 3-only stubs (#6777)

stdlib/multiprocessing/context.pyi

@@ -19,7 +19,7 @@ class BufferTooShort(ProcessError): ...
 class TimeoutError(ProcessError): ...
 class AuthenticationError(ProcessError): ...
 
-class BaseContext(object):
+class BaseContext:
     Process: Type[BaseProcess]
     ProcessError: Type[Exception]
     BufferTooShort: Type[Exception]

stdlib/multiprocessing/dummy/connection.pyi

@@ -7,7 +7,7 @@ families: list[None]
 
 _Address = Union[str, tuple[str, int]]
 
-class Connection(object):
+class Connection:
     _in: Any
     _out: Any
     recv: Any
@@ -22,7 +22,7 @@ class Connection(object):
     def close(self) -> None: ...
     def poll(self, timeout: float = ...) -> bool: ...
 
-class Listener(object):
+class Listener:
     _backlog_queue: Queue[Any] | None
     @property
     def address(self) -> Queue[Any] | None: ...

stdlib/multiprocessing/managers.pyi

@@ -27,7 +27,7 @@ class Namespace:
 
 _Namespace = Namespace
 
-class Token(object):
+class Token:
     typeid: str | bytes | None
     address: tuple[str | bytes, int]
     id: str | bytes | int | None
@@ -36,7 +36,7 @@ class Token(object):
     def __getstate__(self) -> tuple[str | bytes | None, tuple[str | bytes, int], str | bytes | int | None]: ...
     def __setstate__(self, state: tuple[str | bytes | None, tuple[str | bytes, int], str | bytes | int | None]) -> None: ...
 
-class BaseProxy(object):
+class BaseProxy:
     _address_to_local: dict[Any, Any]
     _mutex: Any
     def __init__(