Skip checking subdagslist if taskinstance state is skipped (#40578)

* Skip checking subdagslist if taskinstance state is skipped

* linter fixes

(cherry picked from commit ec5da92)

airflow/api/common/mark_tasks.py

@@ -144,8 +144,12 @@ def set_state(
     confirmed_infos = list(_iter_existing_dag_run_infos(dag, dag_run_ids, session=session))
     confirmed_dates = [info.logical_date for info in confirmed_infos]
 
-    sub_dag_run_ids = list(
-        _iter_subdag_run_ids(dag, session, DagRunState(state), task_ids, commit, confirmed_infos),
+    sub_dag_run_ids = (
+        list(
+            _iter_subdag_run_ids(dag, session, DagRunState(state), task_ids, commit, confirmed_infos),
+        )
+        if not state == TaskInstanceState.SKIPPED
+        else []
     )
 
     # now look for the task instances that are affected