stdlib: Add several missing @abstractmethod decorators (#7443)

stdlib/contextlib.pyi

@@ -137,6 +137,9 @@ elif sys.version_info >= (3, 7):
         func: Callable[..., AsyncGenerator[_T_co, Any]]
         args: tuple[Any, ...]
         kwds: dict[str, Any]
+        async def __aexit__(
+            self, typ: type[BaseException] | None, value: BaseException | None, traceback: TracebackType | None
+        ) -> bool | None: ...
 
 if sys.version_info >= (3, 7):
     def asynccontextmanager(func: Callable[_P, AsyncIterator[_T_co]]) -> Callable[_P, _AsyncGeneratorContextManager[_T_co]]: ...
@@ -148,6 +151,7 @@ _SupportsCloseT = TypeVar("_SupportsCloseT", bound=_SupportsClose)
 
 class closing(AbstractContextManager[_SupportsCloseT]):
     def __init__(self, thing: _SupportsCloseT) -> None: ...
+    def __exit__(self, *exc_info: object) -> None: ...
 
 if sys.version_info >= (3, 10):
     class _SupportsAclose(Protocol):
@@ -156,6 +160,7 @@ if sys.version_info >= (3, 10):
 
     class aclosing(AbstractAsyncContextManager[_SupportsAcloseT]):
         def __init__(self, thing: _SupportsAcloseT) -> None: ...
+        async def __aexit__(self, *exc_info: object) -> None: ...
 
 class suppress(AbstractContextManager[None]):
     def __init__(self, *exceptions: type[BaseException]) -> None: ...
@@ -163,11 +168,14 @@ class suppress(AbstractContextManager[None]):
         self, exctype: type[BaseException] | None, excinst: BaseException | None, exctb: TracebackType | None
     ) -> bool: ...
 
-class redirect_stdout(AbstractContextManager[_T_io]):
+class _RedirectStream(AbstractContextManager[_T_io]):
     def __init__(self, new_target: _T_io) -> None: ...
+    def __exit__(
+        self, exctype: type[BaseException] | None, excinst: BaseException | None, exctb: TracebackType | None
+    ) -> None: ...
 
-class redirect_stderr(AbstractContextManager[_T_io]):
-    def __init__(self, new_target: _T_io) -> None: ...
+class redirect_stdout(_RedirectStream[_T_io]): ...
+class redirect_stderr(_RedirectStream[_T_io]): ...
 
 class ExitStack(AbstractContextManager[ExitStack]):
     def __init__(self) -> None: ...