### 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
"""Home view."""
        unit_test_mode: bool = conf.getboolean('core', 'UNIT_TEST_MODE')
        if not unit_test_mode and "sqlite" in conf.get("core", "sql_alchemy_conn"):
            db_doc_page = get_docs_url("howto/set-up-database.html")
            flash(
                Markup(
                    "Usage of <b>SQLite</b> detected. It should only be used for dev/testing. "
                    "Do not use <b>SQLite</b> as metadata DB in production. "
                    "We recommend using Postgres or MySQL. "
                    f"<a href='{db_doc_page}'><b>Click here</b></a> for more information."
                ),
                category="warning",
            )
        if not unit_test_mode and conf.get("core", "executor") == "SequentialExecutor":
            exec_doc_page = get_docs_url("executor/index.html")
            flash(
                Markup(
                    "Usage of <b>SequentialExecutor</b> detected. "
                    "Do not use <b>SequentialExecutor</b> in production. "
                    f"<a href='{exec_doc_page}'><b>Click here</b></a> for more information."
                ),
                category="warning",
            )
        hide_paused_dags_by_default = conf.getboolean('webserver', 'hide_paused_dags_by_default')