update slot resume pointers for step 3721

slots/3/latest.json

@@ -1 +1 @@
-{"worker_id": "slot:3", "checkpoint": "slots/3/checkpoint-3138", "step": 3138, "updated_at": 1776688724}
+{"worker_id": "slot:3", "checkpoint": "slots/3/checkpoint-3721", "step": 3721, "updated_at": 1776690971}