Release prep v4.19.0

[github-actions[bot]]

Automated release-prep through pdk-templates from commit b8db2ad97ee31da0a7f3bfe88e6cd4f294d58bed. Please verify before merging:

• [x] last nightly run is green
• [x] Changelog is readable and has no unlabeled pull requests
• [x] Ensure the changelog version and metadata version match