[BUG] Multiple tags seem like multiple different images

[treydock]

Describe the bug
When using multiple tags the images end up appearing like different images.

To Reproduce
Build image with --publish-tags <tag1> <tag2> <tag3> and observe the SHA is different for each and push to a registry like Harbor and shows 3 images.

Expected behavior
Expect a single image with many tags to associate all the tags with the same image checksum.

Additional context
Likely requires doing buildah commit with one tag then buildah tag to add the other tags and push them all.

[treydock]

Resolved with #35