Backup Isn't Cleaned Up on Backup Resource Deletion

[millasml]

What happened?

When a backup resource is deleted, the backup agents are deleted as well but the fdbbackup status still reports as running. Combined with #2356, we can run into an issue where:

1. Backup Resource A is created. backup A is running
2. Backup Resource A is deleted. backup A still reports a running state through fdbbackup status, even if there are no backup agents
3. Backup Resource B is created.
4. The reconciler reports Backup Resource B to be running, but to the URL of what is specified in A
5. The system is in an inconsistent state where Backup Resource B is running the backup for A, instead of it's own.

What did you expect to happen?

backup should be aborted on deletion of backup resource.

How can we reproduce it (as minimally and precisely as possible)?

delete a backup resource while it is running.

Anything else we need to know?

No response

FDB Kubernetes operator

$ kubectl fdb version
2.9.0

Kubernetes version

$ kubectl version
Client Version: v1.32.2
Kustomize Version: v5.5.0
Server Version: v1.31.1101```

</details>


### Cloud provider

<details>
aws
</details>