Merge branch 'kassio/fix-pages-unique-domain-redirect-for-root-namespace-urls' into 'master'

Fix pages unique domain redirect

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/118613



Merged-by: Michael Kozono <mkozono@gitlab.com>
Approved-by: Dheeraj Joshi <djoshi@gitlab.com>
Approved-by: Naman Jagdish Gala <ngala@gitlab.com>
Approved-by: Vitaly Slobodin <vslobodin@gitlab.com>
Approved-by: Michael Kozono <mkozono@gitlab.com>
Reviewed-by: Naman Jagdish Gala <ngala@gitlab.com>
Co-authored-by: Dheeraj Joshi <djoshi@gitlab.com>
Co-authored-by: Kassio Borges <kassioborgesm@gmail.com>