Merge branch '439346-yaml-editor-extra-characters' into 'master'

Fix adding extra characters for pipeline execution policy

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/143068



Merged-by: Alexander Turinske <aturinske@gitlab.com>
Approved-by: Martin Čavoj <mcavoj@gitlab.com>
Approved-by: Alexander Turinske <aturinske@gitlab.com>
Reviewed-by: Martin Čavoj <mcavoj@gitlab.com>
Co-authored-by: Artur Fedorov <afedorov@gitlab.com>