With skip digest unchanged it is not enough the push the current tag, which is probably semvar, we also need to push the latest, so we can later check if the latest digest equal current tag
Fixing few issues with digest:
1. Multi-stage dockerfiles override /usr/local/lib, downloading jq and reg to /kaniko instead
2. Github registry doesn't support digest yet, downloading manifest and calculating the digest manually
3. Digest was fetched for the current tag, which not yet exist. Fetching digest for the latest tag instead
