### Body

Add unit test for changes in https://github.com/apache/airflow/pull/17305

### Committer

- [X] I acknowledge that I am a maintainer/committer of the Apache Airflow project.
tests/jobs/test_backfill_job.py
"""
        Test backfilling example dags
        Try to backfill some of the example dags. Be careful, not all dags are suitable
        for doing this. For example, a dag that sleeps forever, or does not have a
        schedule won't work here since you simply can't backfill them.
        """
        dag = self.dagbag.get_dag(dag_id)
        logger.info('*** Running example DAG: %s', dag.dag_id)
        executor = MockExecutor()
        job = BackfillJob(
            dag=dag,
            start_date=DEFAULT_DATE,
            end_date=DEFAULT_DATE,
            executor=executor,
            ignore_first_depends_on_past=True,
        )
        job.run()
        assert [
            ((dag_id, task_id, f'backfill__{DEFAULT_DATE.isoformat()}', 1), (State.SUCCESS, None))
            for task_id in expected_execution_order
        ] == executor.sorted_tasks
    def test_backfill_conf(self, dag_maker):