feat(core): Upgrade pydantic to 2.x (#1428)

dbgpt/serve/conversation/models/models.py

@@ -2,7 +2,6 @@
 You can define your own models and DAOs here
 """
 import json
-from datetime import datetime
 from typing import Any, Dict, List, Optional, Union
 
 from dbgpt.core import MessageStorageItem
@@ -31,7 +30,9 @@ class ServeDao(BaseDao[ServeEntity, ServeRequest, ServerResponse]):
         Returns:
             T: The entity
         """
-        request_dict = request.dict() if isinstance(request, ServeRequest) else request
+        request_dict = (
+            request.to_dict() if isinstance(request, ServeRequest) else request
+        )
         entity = ServeEntity(**request_dict)
         # TODO implement your own logic here, transfer the request_dict to an entity
         return entity