### Apache Airflow version

2.4.2

### What happened

Create a DAG and set the schedule parameter using a CronTriggerTimeTable instance. Enable the DAG so that there is DAG run data. Try to access the Calendar View for the DAG. An ERR_EMPTY_RESPONSE error is displayed instead of the page.

The Calendar View is accessible for other DAGs  that are using the schedule_interval set to a cron string instead.

### What you think should happen instead

The Calendar View should have been displayed.

### How to reproduce

Create a DAG and set the schedule parameter to a CronTriggerTimeTable instance. Enable the DAG and allow some DAG runs to occur. Try to access the Calender View for the DAG.

### Operating System

Red Hat Enterprise Linux 8.6

### Versions of Apache Airflow Providers

_No response_

### Deployment

Virtualenv installation

### Deployment details

Airflow 2.4.2 installed via pip with Python3.9 to venv using constraints.

### Anything else

_No response_

### Are you willing to submit 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)

"""Clears DAG tasks."""
        dag_id = request.form.get("dag_id")
        task_id = request.form.get("task_id")
        origin = get_safe_url(request.form.get("origin"))
        dag = get_airflow_app().dag_bag.get_dag(dag_id)
        group_id = request.form.get("group_id")
        if "map_index" not in request.form:
            map_indexes: list[int] | None = None
        else:
            map_indexes = request.form.getlist("map_index", type=int)
        execution_date_str = request.form.get("execution_date")
        execution_date = _safe_parse_datetime(execution_date_str)
        confirmed = request.form.get("confirmed") == "true"
        upstream = request.form.get("upstream") == "true"
        downstream = request.form.get("downstream") == "true"
        future = request.form.get("future") == "true"
        past = request.form.get("past") == "true"
        recursive = request.form.get("recursive") == "true"
        only_failed = request.form.get("only_failed") == "true"