Add ability to disable a running DAG only after after it's in a finished state

### Description

I'd like the ability to "drain" a DAG from the UI. This would mean:

- If a DAG is in a running state - disable the DAG after the run reaches a finished state (success/failed)
- If a DAG is in an idle state - disable immediately (same as what disable does right now)

### Use case/motivation

Currently, if you disable a DAG, it stops the DAG midway - the running tasks are completed, and queued tasks remain on the queue. I would like a way to disable the DAG, but if there is an active Dag Run it should continue running until it reaches a finished state.

For us, this would be especially helpful when upgrading our Airflow images/environments. To my understanding, Airflow doesn't have a failure-free zero-downtime upgrade (please point me to documentation if its possible). When upgrading, we don't want to fail/kill running DAGs, so we let them reach a finished state. Once none of the DAGs are in a running state, we perform the upgrades. Precisely timing the DAG disable operation such that a subsequent run doesn't start, is not a practical/viable solution.
For upgrades in the past, we have changed all the DAG schedules to None, which allows a running DAG to complete but doesn't start a subsequent run. Once upgrades are done, we update the DAG schedules back to their original value.
We would like to move away from this solution, and have some built-in functionality to deal with such a case.

### 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)