fix: forward socket_timeout and socket_connect_timeout to RedisCluster

_get_redis_cluster_kwargs() filters kwargs before passing them to
redis.RedisCluster(). The allow-list was missing socket_timeout and
socket_connect_timeout, so those values were silently dropped for
cluster clients — causing connections to hang indefinitely on
unreachable nodes.

Add both kwargs to the explicit allow-list so they are forwarded to
redis-py cluster clients, matching the behavior of the non-cluster
Redis path.

Closes #27919

litellm/_redis.py

@@ -100,6 +100,8 @@ def _get_redis_cluster_kwargs(client=None):
         "azure_tenant_id",
         "azure_client_secret",
         "max_connections",
+        "socket_timeout",
+        "socket_connect_timeout",
     }
 
     return available_args