refac: modernize type annotations (PEP 604 / PEP 585)

backend/open_webui/utils/images/comfyui.py

@@ -5,10 +5,9 @@ import urllib.parse
 from typing import Optional
 
 import aiohttp
-from pydantic import BaseModel
-
 from open_webui.env import AIOHTTP_CLIENT_SESSION_SSL
 from open_webui.utils.session_pool import get_session
+from pydantic import BaseModel
 
 log = logging.getLogger(__name__)