### 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
"""Pool link rendering."""
        pool_id = self.get('pool')
        if pool_id is not None:
            url = url_for('TaskInstanceModelView.list', _flt_3_pool=pool_id)
            return Markup("<a href='{url}'>{pool_id}</a>").format(url=url, pool_id=pool_id)
        else:
            return Markup('<span class="label label-danger">Invalid</span>')
    def frunning_slots(self):
        """Running slots rendering."""
        pool_id = self.get('pool')
        running_slots = self.get('running_slots')
        if pool_id is not None and running_slots is not None:
            url = url_for('TaskInstanceModelView.list', _flt_3_pool=pool_id, _flt_3_state='running')
            return Markup("<a href='{url}'>{running_slots}</a>").format(url=url, running_slots=running_slots)
        else:
            return Markup('<span class="label label-danger">Invalid</span>')
    def fqueued_slots(self):
        """Queued slots rendering."""
        pool_id = self.get('pool')
        queued_slots = self.get('queued_slots')
        if pool_id is not None and queued_slots is not None:
            url = url_for('TaskInstanceModelView.list', _flt_3_pool=pool_id, _flt_3_state='queued')
            return Markup("<a href='{url}'>{queued_slots}</a>").format(url=url, queued_slots=queued_slots)
        else:
            return Markup('<span class="label label-danger">Invalid</span>')
    formatters_columns = {'pool': pool_link, 'running_slots': frunning_slots, 'queued_slots': fqueued_slots}
    validators_columns = {'pool': [validators.DataRequired()], 'slots': [validators.NumberRange(min=-1)]}
def _can_create_variable() -> bool:
    return current_app.appbuilder.sm.has_access(permissions.ACTION_CAN_CREATE, permissions.RESOURCE_VARIABLE)
class VariableModelView(AirflowModelView):