Merge branch 'Chantalskye-clarify-domain-restrictions' into 'master'

Clarify domain restrictions

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/141731



Merged-by: Lorena Ciutacu <lciutacu@gitlab.com>
Approved-by: Lorena Ciutacu <lciutacu@gitlab.com>
Co-authored-by: Chantal Lawrence <clawrence@gitlab.com>