Merge branch 'update-ci-vars-line' into 'master'

Update description in CI/CD Variables settings

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/140461



Merged-by: Paul Gascou-Vaillancourt <pgascouvaillancourt@gitlab.com>
Approved-by: Max Fan <mfan@gitlab.com>
Approved-by: Paul Gascou-Vaillancourt <pgascouvaillancourt@gitlab.com>
Reviewed-by: Paul Gascou-Vaillancourt <pgascouvaillancourt@gitlab.com>
Co-authored-by: Mireya Andres <mandres@gitlab.com>