Resolve "Release is failing on master"

What does this MR do?

Overrides image's entrypoint to run sh instead of crane, which fixes the release-tag job.

Manual QA

I've tested it by creating a fake test job that uses crane:debug as an image, but I've already reverted the commit.

This was the job that tested it: https://gitlab.com/gitlab-org/cluster-integration/cluster-applications/-/jobs/1766348315

The MR is setup to squash the commits so the test commit and its revert will be squashed into the main commit which introduces the change and has the proper commit message.

Closes #78 (closed)