[Bugfix] Fix asyncio.Task not being subscriptable (#4623)

vllm/entrypoints/openai/api_server.py

@@ -4,7 +4,7 @@ import inspect
 import re
 from contextlib import asynccontextmanager
 from http import HTTPStatus
-from typing import Any, Set
+from typing import Set
 
 import fastapi
 import uvicorn
@@ -34,7 +34,7 @@ openai_serving_chat: OpenAIServingChat
 openai_serving_completion: OpenAIServingCompletion
 logger = init_logger(__name__)
 
-_running_tasks: Set[asyncio.Task[Any]] = set()
+_running_tasks: Set[asyncio.Task] = set()
 
 
 @asynccontextmanager