chore: remove redundant casting flask app config into dict (#2564)

api/commands.py

@@ -1,7 +1,6 @@
 import base64
 import json
 import secrets
-from typing import cast
 
 import click
 from flask import current_app
@@ -132,7 +131,7 @@ def vdb_migrate():
     """
     click.echo(click.style('Start migrate vector db.', fg='green'))
     create_count = 0
-    config = cast(dict, current_app.config)
+    config = current_app.config
     vector_type = config.get('VECTOR_STORE')
     page = 1
     while True: