fix(data-process): 保留可验证的任务耗时

backend/app/modules/data_process/store.py

@@ -549,10 +549,6 @@ class DataProcessStore:
                 recovered_count += 1
 
             now = utcnow()
-            published_at = max(
-                (dataset.get("created_at") for dataset in datasets if dataset.get("created_at")),
-                default=None,
-            )
             conn.execute(
                 """
                 UPDATE data_process_tasks
@@ -560,15 +556,13 @@ class DataProcessStore:
                     output_count=%s, filtered_count=0, duplicate_count=0,
                     error_count=(SELECT COUNT(*) FROM data_process_results
                                  WHERE task_id=%s AND status='invalid'),
-                    failure_reason=NULL, completed_at=COALESCE(completed_at, %s),
-                    updated_at=%s
+                    failure_reason=NULL, updated_at=%s
                 WHERE id=%s
                 """,
                 (
                     train_dataset["id"],
                     recovered_count,
                     task_id,
-                    published_at,
                     now,
                     task_id,
                 ),