ci: make name for digest artifact unique

[chrisgacsal]

Description

The actions/download-artifact@v4 action used in merge-and-push job uses a pattern filter to find all the digest artifacts uploaded for a specific image in order to combine them into a multi-arch container image. However the current filter set for this action is incorrect as it could allow to fetch digests for images which has similar name as the filter pattern uses the image name as a key.

So using the digests-7755142612-vmclarity-ui-* pattern also includes artifacts with name digests-7755142612-vmclarity-ui-backend-* which is not the desired behavior.

This change fixes this issue by using the SHA256 hash of the image name in the generated digest-cache-name used for naming and filtering the artifacts for image digests. This way we can reduce the chance for naming collisions.

Type of Change

[x] Bug Fix
[ ] New Feature
[ ] Breaking Change
[ ] Refactor
[ ] Documentation
[ ] Other (please describe)

Checklist

• I have read the contributing guidelines
• Existing issues have been referenced (where applicable)
• I have verified this change is not present in other open pull requests
• Functionality is documented
• All code style checks pass
• New code contribution is covered by automated tests
• All new and existing tests pass

[github-actions]

Hey!

Your images are ready:

• ghcr.io/openclarity/vmclarity-apiserver-dev:pr1156-06e1d8c7216b886947f5f390ef51c4eb49170fbd
• ghcr.io/openclarity/vmclarity-orchestrator-dev:pr1156-06e1d8c7216b886947f5f390ef51c4eb49170fbd
• ghcr.io/openclarity/vmclarity-ui-backend-dev:pr1156-06e1d8c7216b886947f5f390ef51c4eb49170fbd
• ghcr.io/openclarity/vmclarity-ui-dev:pr1156-06e1d8c7216b886947f5f390ef51c4eb49170fbd
• ghcr.io/openclarity/vmclarity-cli-dev:pr1156-06e1d8c7216b886947f5f390ef51c4eb49170fbd
• ghcr.io/openclarity/vmclarity-cr-discovery-server-dev:pr1156-06e1d8c7216b886947f5f390ef51c4eb49170fbd