Reconcile multi arch support for push-image workflow

[pacostas]

Summary

This PR reconciles the implementation of push-image workflow for a single architecture with the multi-arch one that currently exists on jammy-tiny-stack.

In addition to push-image.yml changes, this PR adds an extra script called publish.sh, which pushes the images to the registry. The publish.sh is based on the multiarch implementation script that exists on jammy-tiny-stack https://github.com/paketo-buildpacks/jammy-tiny-stack/blob/main/scripts/publish.sh and in addition extra functionality has been added, to push one image per time instead of two images per time, as jam now supports this feature paketo-buildpacks/jam#346 . The default functionality of the publis.sh script has not been changed.

This PR has been tested that pushes the images properly to the registries. Test results :

• ubi-base-stack: https://github.com/pacostas/ubi-base-stack/actions/runs/11216366589
• jammy-tiny-stack: https://github.com/pacostas/jammy-tiny-stack/actions/runs/11218960285
• jammy-base-stack: https://github.com/pacostas/jammy-base-stack/actions/runs/11343601624

This PR does not change any of the current functionality of the stacks while pushing to registry. It only adds new functionality which enables single and multi arch implementation to publish their images.

Use Cases

Checklist

• I have viewed, signed, and submitted the Contributor License Agreement.
• I have linked issue(s) that this PR should close using keywords or the Github UI (See docs)
• I have added an integration test, if necessary.
• I have reviewed the styleguide for guidance on my code quality.
• I'm happy with the commit history on this PR (I have rebased/squashed as needed).

[pacostas]

@ForestEckhardt