Separate the CI from the publish job

[cmoulliard]

TODO

Comment from #40

Error: Command failed: DOCKER_BUILDKIT=1 docker buildx build -f Dockerfile -t [quay.io/snowdrop/cert-manager-webhook-godaddy:pr-40-0da9b20](http://quay.io/snowdrop/cert-manager-webhook-godaddy:pr-40-0da9b20) -t [quay.io/snowdrop/cert-manager-webhook-godaddy](http://quay.io/snowdrop/cert-manager-webhook-godaddy):latest --platform linux/amd64,linux/arm64 --push .

I normally separate my CI job from the publish job. Publish job could after PR is merged:
[quay.io/snowdrop/cert-manager-webhook-godaddy:latest](http://quay.io/snowdrop/cert-manager-webhook-godaddy:latest)

CI build (before PR is merged) maybe a git reference tag instead of latest.

@bordenit