fix: xxx is not bound to a Session (#24966)

api/core/app/apps/advanced_chat/app_generator.py

         # release database connection, because the following new thread operations may take a long time
         db.session.refresh(workflow)
         db.session.refresh(message)
-        db.session.refresh(user)
+        # db.session.refresh(user)
         db.session.close()
 
         # return response or stream generator

api/services/account_service.py

         if naive_utc_now() - account.last_active_at > timedelta(minutes=10):
             account.last_active_at = naive_utc_now()
             db.session.commit()
-
+        # NOTE: make sure account is accessible outside of a db session
+        # This ensures that it will work correctly after upgrading to Flask version 3.1.2
+        db.session.refresh(account)
+        db.session.close()
         return account
 
     @staticmethod