ExternalTaskSensor waits forever if TaskGroup contains skipped tasks

### Apache Airflow version Other Airflow 2 version (please specify below) ### What happened If you have an `ExternalTaskSensor` that uses `external_task_group_id` to wait on a `TaskGroup`, and if that `TaskGroup` contains any skipped tasks, the sensor will be stuck waiting forever despite the UI saying the state of the `TaskGroup` is successful. ### What you think should happen instead `ExternalTaskSensor` should match the UI's interpretation of the `TaskGroup` state. ### How to reproduce ``` #!/usr/bin/env python3 import datetime import logging from airflow.decorators import dag, task from airflow.operators.empty import EmptyOperator from airflow.sensors.external_task import ExternalTaskSensor from airflow.utils.task_group import TaskGroup from airflow.exceptions import AirflowFailException, AirflowSkipException logger = logging.getLogger(__name__) @dag( schedule_interval='@daily', start_date=datetime.datetime(2023, 8, 1), ) def task_groups(): with TaskGroup(group_id='skip_group'): @task def skip_task(): raise AirflowSkipException EmptyOperator(task_id='operator1') >> skip_task() with TaskGroup(group_id='pass_group'): @task def pass_task(): pass EmptyOperator(task_id='operator3') >> pass_task() ExternalTaskSensor( task_id='wait_for_task_group_with_skipped_task', external_dag_id='task_groups', external_task_group_id='skip_group', check_existence=True, ) ExternalTaskSensor( task_id='wait_for_task_group_with_passed_task', external_dag_id='task_groups', external_task_group_id='pass_group', check_existence=True, ) dag = task_groups() if __name__ == '__main__': dag.cli() ``` ### Operating System CentOS Stream 8 ### Versions of Apache Airflow Providers _No response_ ### Deployment Other ### Deployment details Standalone ### Anything else _No response_ ### Are you willing to submit PR? - [ ] Yes I am wil…