refac: reranker

Co-Authored-By: Tornike Gurgenidze <togurg14@freeuni.edu.ge>

backend/open_webui/retrieval/models/external.py

@@ -3,12 +3,14 @@ import requests
 from typing import Optional, List, Tuple
 
 from open_webui.env import SRC_LOG_LEVELS
+from open_webui.retrieval.models.base_reranker import BaseReranker
+
 
 log = logging.getLogger(__name__)
 log.setLevel(SRC_LOG_LEVELS["RAG"])
 
 
-class ExternalReranker:
+class ExternalReranker(BaseReranker):
     def __init__(
         self,
         api_key: str,