Drop Python 3.8 branches (#13776)

stdlib/asyncio/queues.pyi

@@ -1,10 +1,8 @@
 import sys
 from asyncio.events import AbstractEventLoop
+from types import GenericAlias
 from typing import Any, Generic, TypeVar
 
-if sys.version_info >= (3, 9):
-    from types import GenericAlias
-
 if sys.version_info >= (3, 10):
     from .mixins import _LoopBoundMixin
 else:
@@ -48,8 +46,7 @@ class Queue(Generic[_T], _LoopBoundMixin):  # noqa: Y059
     def get_nowait(self) -> _T: ...
     async def join(self) -> None: ...
     def task_done(self) -> None: ...
-    if sys.version_info >= (3, 9):
-        def __class_getitem__(cls, type: Any, /) -> GenericAlias: ...
+    def __class_getitem__(cls, type: Any, /) -> GenericAlias: ...
     if sys.version_info >= (3, 13):
         def shutdown(self, immediate: bool = False) -> None: ...