### Apache Airflow version

2.2.0 (latest released)

### Operating System

Mac

### Versions of Apache Airflow Providers

_No response_

### Deployment

Other Docker-based deployment

### Deployment details

_No response_

### What happened

Getting an exception when returning None from next_dagrun_info in a custom timetable. The timetable protocol says that when None is returned a DagRun will not happen but right now it throws an exception.

Exception:
```
Traceback (most recent call last):
  File "/home/airflow/.local/lib/python3.9/site-packages/airflow/jobs/scheduler_job.py", line 623, in _execute
    self._run_scheduler_loop()
  File "/home/airflow/.local/lib/python3.9/site-packages/airflow/jobs/scheduler_job.py", line 704, in _run_scheduler_loop
    num_queued_tis = self._do_scheduling(session)
  File "/home/airflow/.local/lib/python3.9/site-packages/airflow/jobs/scheduler_job.py", line 787, in _do_scheduling
    callback_to_run = self._schedule_dag_run(dag_run, session)
  File "/home/airflow/.local/lib/python3.9/site-packages/airflow/jobs/scheduler_job.py", line 1039, in _schedule_dag_run
    self._update_dag_next_dagruns(dag, dag_model, active_runs)
  File "/home/airflow/.local/lib/python3.9/site-packages/airflow/jobs/scheduler_job.py", line 930, in _update_dag_next_dagruns
    data_interval = dag.get_next_data_interval(dag_model)
  File "/home/airflow/.local/lib/python3.9/site-packages/airflow/models/dag.py", line 629, in get_next_data_interval
    return self.infer_automated_data_interval(dag_model.next_dagrun)
  File "/home/airflow/.local/lib/python3.9/site-packages/airflow/models/dag.py", line 671, in infer_automated_data_interval
    raise ValueError(f"Not a valid timetable: {self.timetable!r}")
ValueError: Not a valid timetable: <my_timetables.workday_timetable.WorkdayTimetable object at 0x7f42b1f02430>
```

### What you expected to happen

DagRun to not happen.

### How to reproduce

Create a custom timetable and return None in next_dagrun_info after a few DagRuns are created by that timetable

### Anything else

_No response_

### Are you willing to submit PR?

- [ ] 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)

tests/models/test_dag.py
"""Test that set_task_instance_state updates the TaskInstance state and clear downstream failed"""
    start_date = datetime_tz(2020, 1, 1)
    with dag_maker("test_set_task_instance_state", start_date=start_date, session=session) as dag:
        task_1 = DummyOperator(task_id="task_1")
        task_2 = DummyOperator(task_id="task_2")
        task_3 = DummyOperator(task_id="task_3")
        task_4 = DummyOperator(task_id="task_4")
        task_5 = DummyOperator(task_id="task_5")
        task_1 >> [task_2, task_3, task_4, task_5]
    dagrun = dag_maker.create_dagrun(state=State.FAILED, run_type=DagRunType.SCHEDULED)
    def get_ti_from_db(task):
        return (
            session.query(TI)
            .filter(
                TI.dag_id == dag.dag_id,
                TI.task_id == task.task_id,
                TI.run_id == dagrun.run_id,
            )
            .one()
        )
    get_ti_from_db(task_1).state = State.FAILED
    get_ti_from_db(task_2).state = State.SUCCESS
    get_ti_from_db(task_3).state = State.UPSTREAM_FAILED
    get_ti_from_db(task_4).state = State.FAILED
    get_ti_from_db(task_5).state = State.SKIPPED
    session.flush()
    altered = dag.set_task_instance_state(
        task_id=task_1.task_id, execution_date=start_date, state=State.SUCCESS, session=session
    )