### 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
def trigger(self, session=None):
        """Triggers DAG Run."""
        dag_id = request.values.get('dag_id')
        origin = get_safe_url(request.values.get('origin'))
        unpause = request.values.get('unpause')
        request_conf = request.values.get('conf')
        request_execution_date = request.values.get('execution_date', default=timezone.utcnow().isoformat())
        if request.method == 'GET':
            
            default_conf = ''
            dag = current_app.dag_bag.get_dag(dag_id)
            doc_md = wwwutils.wrapped_markdown(getattr(dag, 'doc_md', None))
            form = DateTimeForm(data={'execution_date': request_execution_date})
            if request_conf:
                default_conf = request_conf
            else:
                try:
                    default_conf = json.dumps(dag.params, indent=4)
                except TypeError:
                    flash("Could not pre-populate conf field due to non-JSON-serializable data-types")
            return self.render_template(
                'airflow/trigger.html',
                dag_id=dag_id,
                origin=origin,
                conf=default_conf,
                doc_md=doc_md,
                form=form,
            )
        dag_orm = session.query(models.DagModel).filter(models.DagModel.dag_id == dag_id).first()
        if not dag_orm: