ci: make jobs retriable and interruptible
Since adding a test matrix for all supported k8s versions, we have been having problems with flaky jobs due to networking errors. We need these to be retriable, as otherwise merge trains fail excessively.
We make the jobs interruptible to save on resources when iterating on merge requests.
Example MR that failed two consecutive merge trains: !169 (merged)
Edited by Hordur Freyr Yngvason