### Description

Auto-refresh is an awesome new feature! Right now it occurs every [3 seconds](https://github.com/apache/airflow/blob/79d85573591f641db4b5f89a12213e799ec6dea1/airflow/www/static/js/tree.js#L463), and this interval is not configurable. Making this interval configurable would be useful.

### Use case/motivation

On a DAG with many tasks and many active DAG runs, auto-refresh can be a significant strain on the webserver. We observed our production webserver reach 100% CPU today when we had about 30 running DAG runs of a DAG containing about 50 tasks. Being able to increase the interval to guard against this would be helpful.

### Related issues

_No response_

### 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)

airflow/www/views.py
last_runs_subquery.c.dag_id == DagRun.dag_id,
                last_runs_subquery.c.max_execution_date == DagRun.execution_date,
            ),
        )
        def _datetime_to_string(value: Optional[DateTime]) -> Optional[str]:
            if value is None:
                return None
            return value.isoformat()
        resp = {
            r.dag_id.replace('.', '__dot__'): {
                "dag_id": r.dag_id,
                "state": r.state,
                "execution_date": _datetime_to_string(r.execution_date),
                "start_date": _datetime_to_string(r.start_date),
                "end_date": _datetime_to_string(r.end_date),
                "data_interval_start": _datetime_to_string(r.data_interval_start),
                "data_interval_end": _datetime_to_string(r.data_interval_end),
            }
            for r in query
        }
        return wwwutils.json_response(resp)
    @expose('/code')
    @auth.has_access(
        [
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG),
            (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG_CODE),
        ]
    )
    @provide_session
    def code(self, session=None):