Description
Create a GitHub action workflow that promotes CLI Release Candidates (RCs) to Final releases. No rebuild is allowed at promotion time.

Prerequisites:
RCs for all components to be promoted exist in a release branch (created using e.g. CLI release)

Simplification for first version
Support only parallel promotion of all components based on a common RC (also for patches). Input for the workflow is a single RC, e.g. v0.1.0-rc.2 which needs to exist for all components.

Requirements:

• Works on component tags + unified releases/X.Y branch
• Input: release branch and common RC
• Download and verify checksums of RC release assets
• Verify RC attestations for binaries and OCI images
• Reuse RC assets
• Retag RC OCI images
• Convert GitHub pre-releases into Final, including release notes

Since attestations are bound to subjects digests and the final release get the same assets as the RC, attestations are valid for both, RC and Finals, and do not need to be created again.

Done Criteria

• Workflow can be triggered via workflow_dispatch
• Final release references the exact same artifacts (same digests).
• Existing RC GitHub pre-releases are promoted by metadata update
• Existing attestations for artifacts remain valid
• Clear error handling and job summary
• Code is reviewed; user & technical docs updated; demo conducted in Review