Enforce Conventional Commit Messages

[vorburger]

Add https://github.com/jorisroovers/gitlint to .pre-commit-config.yaml, to enforce https://www.conventionalcommits.org like git commit messages.

See existing commits, and start e.g. with feat|model|fix|build|docs|clean|format|refactor and (comm|core|k8s|tools|docs).

[aalmiray]

Additionally https://github.com/Ezard/semantic-prs may be used as a GitHub action to validate PRs in case contributors did not configure git hooks.