Use PEP 585 syntax in Python 2, protobuf & _ast stubs, where possible (#6949)

stubs/futures/@python2/concurrent/futures/_base.pyi

@@ -3,7 +3,7 @@ from _typeshed import Self
 from abc import abstractmethod
 from logging import Logger
 from types import TracebackType
-from typing import Any, Callable, Container, Generic, Iterable, Iterator, List, Optional, Protocol, Set, Tuple, TypeVar
+from typing import Any, Callable, Container, Generic, Iterable, Iterator, Optional, Protocol, TypeVar
 
 FIRST_COMPLETED: str
 FIRST_EXCEPTION: str
@@ -41,7 +41,7 @@ class Future(Generic[_T]):
     def set_running_or_notify_cancel(self) -> bool: ...
     def set_result(self, result: _T) -> None: ...
     def exception(self, timeout: Optional[float] = ...) -> Any: ...
-    def exception_info(self, timeout: Optional[float] = ...) -> Tuple[Any, Optional[TracebackType]]: ...
+    def exception_info(self, timeout: Optional[float] = ...) -> tuple[Any, Optional[TracebackType]]: ...
     def set_exception(self, exception: Any) -> None: ...
     def set_exception_info(self, exception: Any, traceback: Optional[TracebackType]) -> None: ...
 
@@ -55,11 +55,11 @@ class Executor:
 def as_completed(fs: Iterable[Future[_T]], timeout: Optional[float] = ...) -> Iterator[Future[_T]]: ...
 def wait(
     fs: _Collection[Future[_T]], timeout: Optional[float] = ..., return_when: str = ...
-) -> Tuple[Set[Future[_T]], Set[Future[_T]]]: ...
+) -> tuple[set[Future[_T]], set[Future[_T]]]: ...
 
 class _Waiter:
     event: threading.Event
-    finished_futures: List[Future[Any]]
+    finished_futures: list[Future[Any]]
     def __init__(self) -> None: ...
     def add_result(self, future: Future[Any]) -> None: ...
     def add_exception(self, future: Future[Any]) -> None: ...