### Description

https://github.com/apache/airflow/pull/17946 implements a `/robots.txt` endpoint to block search engines crawling Airflow - in the cases where it is (accidentally) exposed to the public Internet.

If we record any GET requests to that end-point we'd have a strong warning flag that the deployment is exposed, and could issue a warning in the UI, or even enable some kill-switch on the deployment. 

Some deployments are likely intentionally available and rely on auth mechanisms on the `login` endpoint, so there should be a config option to suppress the warnings.

An alternative approach would be to monitor for requests from specific user-agents used by crawlers for the same reasons

### Use case/motivation

People who accidentally expose airflow have a slightly higher chance of realising they've done so and tighten their security.

### Related issues

_No response_

### Are you willing to submit a PR?

- [ ] 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
permissions.ACTION_CAN_EDIT,
        permissions.ACTION_CAN_DELETE,
        permissions.ACTION_CAN_ACCESS_MENU,
    ]
    page_size = PAGE_SIZE
    list_columns = [
        'state',
        'dag_id',
        'task_id',
        'run_id',
        'dag_run.execution_date',
        'operator',
        'start_date',
        'end_date',
        'duration',
        'job_id',
        'hostname',
        'unixname',
        'priority_weight',
        'queue',
        'queued_dttm',
        'try_number',
        'pool',
        'queued_by_job_id',
        'external_executor_id',
        'log_url',
    ]
    order_columns = [
        item for item in list_columns if item not in ['try_number', 'log_url', 'external_executor_id']
    ]