Merge branch '20250304-clavimoniere-help-center-a11y' into 'master'

Improve a11y of Help menu

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/183443



Merged-by: Stanislav Lashmanov <slashmanov@gitlab.com>
Approved-by: Annabel Dunstone Gray <annabel.dunstone@gmail.com>
Approved-by: Stanislav Lashmanov <slashmanov@gitlab.com>
Reviewed-by: Annabel Dunstone Gray <annabel.dunstone@gmail.com>
Co-authored-by: Chad Lavimoniere <clavimoniere@gitlab.com>