### 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
{"name": name, "selected": bool(arg_tags_filter and name in arg_tags_filter)}
                for name, in dagtags
            ]
            import_errors = session.query(errors.ImportError).order_by(errors.ImportError.id)
            if (permissions.ACTION_CAN_READ, permissions.RESOURCE_DAG) not in user_permissions:
                
                import_errors = import_errors.join(
                    DagModel, DagModel.fileloc == errors.ImportError.filename
                ).filter(DagModel.dag_id.in_(filter_dag_ids))
            for import_error in import_errors:
                flash(
                    "Broken DAG: [{ie.filename}] {ie.stacktrace}".format(ie=import_error),
                    "dag_import_error",
                )
        from airflow.plugins_manager import import_errors as plugin_import_errors
        for filename, stacktrace in plugin_import_errors.items():
            flash(
                f"Broken plugin: [{filename}] {stacktrace}",
                "error",
            )
        num_of_pages = int(math.ceil(num_of_all_dags / float(dags_per_page)))
        state_color_mapping = State.state_color.copy()
        state_color_mapping["null"] = state_color_mapping.pop(None)
        page_title = conf.get(section="webserver", key="instance_name", fallback="DAGs")
        return self.render_template(
            'airflow/dags.html',
            dags=dags,
            current_page=current_page,
            search_query=arg_search_query if arg_search_query else '',
            page_title=page_title,