chore: make sure we pass the right values back to core when cancelling a task

[shreddedbacon]

Checklist

• Affected Issues have been mentioned in the Closing issues section
• Documentation has been written/updated
• PR title is ready for changelog and subsystem label(s) applied

When cancelling a task that no longer exists in the cluster, we need to pass back some values in the response so the actions-handler knows how to cancel the task properly.

Part of uselagoon/lagoon#3112 but can be merged and released prior to the core pullrequest