Fix unable to rollback due to dropped not null constraint on 50 (#44886)

dev/src/dev/migrate.clj

@@ -42,7 +42,7 @@
                       :where  [:> :orderexecuted {:select   [:orderexecuted]
                                                   :from     [:databasechangelog]
                                                   :where    [:like :id (format "%s%%" id)]
-                                                  :order-by [:orderexecuted :desc]
+                                                  :order-by [[:orderexecuted :desc]]
                                                   :limit    1}]
                       :limit 1})
        :count

resources/migrations/001_update_migrations.yaml

@@ -7564,6 +7564,7 @@ databaseChangeLog:
             tableName: task_history
             columnDataType: ${timestamp_type}
             columnName: ended_at
+      rollback: # we can't reliably add back the constraint while downgrading
 
   - changeSet:
       id: v50.2024-05-08T09:00:04
@@ -7574,6 +7575,7 @@ databaseChangeLog:
             tableName: task_history
             columnDataType: int
             columnName: duration
+      rollback: # we can't reliably add back the constraint while downgrading
 
   - changeSet:
       id: v50.2024-05-08T09:00:05