Allow multiple requirements for custom abilities

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/141489



Merged-by: Stan Hu <stanhu@gmail.com>
Approved-by: Tiger Watson <twatson@gitlab.com>
Approved-by: Stan Hu <stanhu@gmail.com>
Reviewed-by: Tiger Watson <twatson@gitlab.com>
Reviewed-by: Alex Buijs <abuijs@gitlab.com>
Co-authored-by: Alex Buijs <abuijs@gitlab.com>