feat: rename ntu img to ruby

utils/completion_reward.py

@@ -165,7 +165,7 @@ class CompletionReward:
             "mtk_response_time": self.mtk_response_time,
             "ntu_response_time": self.ntu_response_time,
             "player_certificate_url": self.player_certificate_url,
-            "created_at_date": datetime.now().date(),
+            "created_at": datetime.now(),
         }
 
     def insert_data_into_bigquery(self, client, dataset_id, table_id, rows_to_insert):