### 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
'latest_heartbeat',
        'executor_class',
        'hostname',
        'unixname',
    ]
    search_columns = [
        'id',
        'dag_id',
        'state',
        'job_type',
        'start_date',
        'end_date',
        'latest_heartbeat',
        'executor_class',
        'hostname',
        'unixname',
    ]
    base_order = ('start_date', 'desc')
    base_filters = [['dag_id', DagFilter, lambda: []]]
    formatters_columns = {
        'start_date': wwwutils.datetime_f('start_date'),
        'end_date': wwwutils.datetime_f('end_date'),
        'hostname': wwwutils.nobr_f('hostname'),
        'state': wwwutils.state_f,
        'latest_heartbeat': wwwutils.datetime_f('latest_heartbeat'),
    }
class DagRunModelView(AirflowPrivilegeVerifierModelView):
    """View to show records from DagRun table"""
    route_base = '/dagrun'
    datamodel = AirflowModelView.CustomSQLAInterface(models.DagRun)