This fixes the said issue by additionally treating any runner pod whose phase is Failed or the runner container exited with non-zero code as "complete" so that ARC gives up unregistering the runner from Actions, deletes the runner pod anyway.
Note that there are a plenty of causes for that. If you are deploying runner pods on AWS spot instances or GCE preemptive instances and a job assigned to a runner took more time than the shutdown grace period provided by your cloud provider (2 minutes for AWS spot instances), the runner pod would be terminated prematurely without letting actions/runner unregisters itself from Actions. If your VM or hypervisor failed then runner pods that were running on the node will become PodFailed without unregistering runners from Actions.
Please beware that it is currently users responsibility to clean up any dangling runner resources on GitHub Actions.
Ref https://github.com/actions-runner-controller/actions-runner-controller/issues/1307
Might also relate to https://github.com/actions-runner-controller/actions-runner-controller/issues/1273
b09c54045a