Buildx workflow now waits for tests to pass before building/uploading
new images.
There's also a separate step for building a properly formatted tag image
if triggered by a new tag.
There doesn't really need to be a 'develop' branch anymore, since all
work is committed directly to 'main', with tags to indicate
production-ready builds.
As a result, the buildx-dev workflow is pretty pointless.
Since Docker Hub no longer allows automated builds for free tier users,
the build process for new images needs to be moved to GitHub Actions.
The existing buildx workflow has worked pretty well for the most part,
but was only enabled for the develop branch and only pushed the
buildx-experimental tag. This addition allows pushes to the main branch
to build updates for the "latest" tag as well, which is more commonly
used I think.
Also added debug to list architectures for buildx. Needless to say,
the buildx action is super flakey (as evidenced by a change to the
README breaking the entire build somehow).
Ben Busby