update slot resume pointers for step 7873

slots/15/latest.json

@@ -1 +1 @@
-{"worker_id": "slot:15", "checkpoint": "slots/15/checkpoint-6323", "step": 6323, "updated_at": 1776740873}
+{"worker_id": "slot:15", "checkpoint": "slots/15/checkpoint-7873", "step": 7873, "updated_at": 1776774445}