example for rm extra cast (#24646)

api/core/rag/datasource/vdb/tidb_on_qdrant/tidb_on_qdrant_vector.py

@@ -3,7 +3,7 @@ import os
 import uuid
 from collections.abc import Generator, Iterable, Sequence
 from itertools import islice
-from typing import TYPE_CHECKING, Any, Optional, Union, cast
+from typing import TYPE_CHECKING, Any, Optional, Union
 
 import qdrant_client
 import requests
@@ -398,7 +398,6 @@ class TidbOnQdrantVector(BaseVector):
 
     def _reload_if_needed(self):
         if isinstance(self._client, QdrantLocal):
-            self._client = cast(QdrantLocal, self._client)
             self._client._load()
 
     @classmethod