Build fails if one base image is a substring of another.

[ralphbean]

I had a build that had two FROM lines, one was registry.access.redhat.com/ubi9/ubi:latest and the other was registry.access.redhat.com/ubi9:latest.

The build failed later on when trying to inject the base image references into the SBOM because the /shared/base_image_digests file had an invalid format.

I think the culprit is the buildah images --format '{{ .Name }}:{{ .Tag }}@{{ .Digest }}' --filter reference="$image" invocation, which (I think) limits the list of images returned to only ones that match the string $image as a filter. That would at least make sense why this shows up as an error when one base/builder image is a substring of another.

Related: #1790