feat: Deprecate datetime.utcnow() in favor of datetime.now(timezone.utc).replace(tzinfo=None) for better timezone handling (#3408) (#3416)

api/core/agent/base_agent_runner.py

@@ -1,7 +1,7 @@
 import json
 import logging
 import uuid
-from datetime import datetime
+from datetime import datetime, timezone
 from typing import Optional, Union, cast
 
 from core.agent.entities import AgentEntity, AgentToolEntity
@@ -440,7 +440,7 @@ class BaseAgentRunner(AppRunner):
             ToolConversationVariables.conversation_id == self.message.conversation_id,
         ).first()
 
-        db_variables.updated_at = datetime.utcnow()
+        db_variables.updated_at = datetime.now(timezone.utc).replace(tzinfo=None)
         db_variables.variables_str = json.dumps(jsonable_encoder(tool_variables.pool))
         db.session.commit()
         db.session.close()