Update dag endpoint tests to include dags with deadlines

### Description Need to update tests to create DAGs with deadlines as below: ``` with dag_maker( DAG1_ID, dag_display_name=DAG1_DISPLAY_NAME, schedule=None, start_date=DAG1_START_DATE, doc_md="details", default_args={ "depends_on_past": False, "retries": 1, "retry_delay": timedelta(minutes=5), }, deadline=[DeadlineAlert( reference=DeadlineReference.DAGRUN_LOGICAL_DATE, interval=timedelta(hours=1), callback="dummy.callback", )], params={"foo": 1}, tags=["example"], ): EmptyOperator(task_id=TASK_ID) ``` ### Use case/motivation _No response_ ### Related issues related to https://github.com/apache/airflow/issues/50574 ### Are you willing to submit a PR? - [x] Yes I am willing to submit a PR! ### Code of Conduct - [x] I agree to follow this project's [Code of Conduct](https://github.com/apache/airflow/blob/main/CODE_OF_CONDUCT.md)