[CI] Address Node.js 20 action deprecation warnings before June 2, 2026

[c-vigo]

Context

Release workflow run #23201577188 shows Node.js 20 deprecation warnings:

• Build and Test (amd64): actions/cache@0400d5f... uses Node.js 20
• Build and Test (arm64): actions/cache@0400d5f... uses Node.js 20
• Publish Release: anchore/sbom-action@57aae52... uses Node.js 20

GitHub warning indicates JavaScript actions will default to Node.js 24 starting June 2, 2026.

Goal

Remove or mitigate Node.js 20 runtime dependencies in release CI ahead of the deadline.

Scope

• Investigate transitive actions/cache@0400d5f... source (likely via docker/build-push-action) and upgrade to a Node.js 24-compatible path.
• Investigate anchore/sbom-action Node.js 24 readiness.
• If upstream does not support Node.js 24 in time, define fallback implementation (e.g., SBOM generation via CLI) and migration path.

Acceptance Criteria

• release.yml no longer emits Node.js 20 deprecation warnings for action runtimes, or
• An explicit documented temporary exception exists with owner + follow-up date if blocked by upstream.
• Validation run confirms current status and remaining risk.