ci: `release-plz` step runs very slowly

The `release-plz` step runs very slowly. We should check if there is a way to cache part of this step because otherwise it appears to be rebuilding everything from scratch, every single time.

Look at the GitHub Actions workflow file (likely .github/workflows/release.yml) to find the 'release-plz' step. Investigate the release-plz tool's documentation for caching options. Check if dependencies or build artifacts can be cached to speed up the step. Verify the improvement by running a test workflow.

Scritto dal modello di indicizzazione a partire dal testo della issue.