Merge branch 'master' into 'master'

fix: allow `artifacts: null` in gitlab ci schema

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/164329



Merged-by: Laura Montemayor <lmontemayor@gitlab.com>
Approved-by: Janis Altherr <jaltherr@gitlab.com>
Approved-by: Laura Montemayor <lmontemayor@gitlab.com>
Co-authored-by: Torben Bühler <torben.buehler@inform-software.com>