fix(mcp): declare the redis key family on the semantic index lock check

Co-Authored-By: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>

litellm/proxy/_experimental/mcp_server/semantic_tool_index_store.py

@@ -80,6 +80,7 @@ class RedisToolVectorStore:
             self._degraded = True
             verbose_logger.warning("MCP semantic tool index store put_many failed; vectors stay local: %s", e)
 
+    @with_service_target(_CACHE_TARGET)
     async def try_acquire_build_lock(self) -> bool:
         # PodLockManager returns False on Redis errors too; once degraded, embed locally instead of waiting.
         try: