Integration tests failing: unsupported MIME type

[shrink]

Started failing a few weeks ago without any changes to the action so the issue is likely outside of the action.

unsupported MIME type for compression: application/vnd.in-toto+json

https://github.com/shrink/actions-docker-registry-tag/actions/runs/7347727035/job/20004627646

Error message referenced in containers/skopeo#2174 and the timeline lines up so likely the same issue.