Remove check if runner exists after exit code 0

[nikola-jokic]

When the runner exits, we check if it still exists within the actions service. If it doesn't, we mark it as finished.

There is a delay between runners being deleted, so the check can rarely return an incorrect result.

This change aims to remove this check completely. The ephemeral runner controller will only react to the exit code of the runner. If the runner exits with the exit code 0, that means that the runner has successfully executed the job.

Fixes #4136

[Copilot]

Pull Request Overview

This PR removes the check that verifies whether a runner exists within the service after the runner Pod exits with code 0 and simplifies the success handling in the EphemeralRunner controller.

• Removed test case for verifying runner existence after exit 0
• Eliminated the logic to query the actions service to check the runner registration
• Cleaned up the now-unused helper function runnerRegisteredWithService

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
controllers/actions.github.com/ephemeralrunner_controller_test.go	Removed obsolete test case for runner existence after successful exit
controllers/actions.github.com/ephemeralrunner_controller.go	Simplified controller logic by removing the redundant runner check

[JohnYoungers]

would it be possible to publish a patch release based on this fix? I think everyone currently playing the recurring delete ephemeralrunner {old-runner} game would appreciate it