[release-v1.15] Bump knative.dev/hack to 1.15 backport#1716

cardil wants to merge 2 commits intoopenshift-knative:release-v1.15openshift-knative/eventing:release-v1.15from

cardil:midstream/bugfix/1.15/restore-buildcardil/knative-eventing:midstream/bugfix/1.15/restore-buildCopy head branch name to clipboard