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

backend/open_webui/models/shared_chats.py

@@ -3,12 +3,10 @@ import time
 import uuid
 from typing import Optional
 
-from sqlalchemy import select, delete
-from sqlalchemy.ext.asyncio import AsyncSession
 from open_webui.internal.db import Base, JSONField, get_async_db_context
-
 from pydantic import BaseModel, ConfigDict
-from sqlalchemy import BigInteger, Column, ForeignKey, Text, JSON
+from sqlalchemy import JSON, BigInteger, Column, ForeignKey, Text, delete, select
+from sqlalchemy.ext.asyncio import AsyncSession
 
 log = logging.getLogger(__name__)