refactor: remove unnecessary type casting in search() function (#153)

fix: Mypy error

server/graph_service/routers/retrieve.py

@@ -1,5 +1,4 @@
 from datetime import datetime
-from typing import List, Optional, cast
 
 from fastapi import APIRouter, status
 
@@ -18,9 +17,7 @@ router = APIRouter()
 @router.post('/search', status_code=status.HTTP_200_OK)
 async def search(query: SearchQuery, graphiti: ZepGraphitiDep):
     relevant_edges = await graphiti.search(
-        group_ids=cast(
-            Optional[List[Optional[str]]], query.group_ids
-        ),  # Cast query.group_ids to match the expected type in graphiti.search
+        group_ids=query.group_ids,
         query=query.query,
         num_results=query.max_facts,
     )