update slot resume pointers for step 4678

slots/7/latest.json

@@ -1 +1 @@
-{"worker_id": "slot:7", "checkpoint": "slots/7/checkpoint-1321", "step": 1321, "updated_at": 1776682367}
+{"worker_id": "slot:7", "checkpoint": "slots/7/checkpoint-4678", "step": 4678, "updated_at": 1776735106}