Merge branch 'mokhax/417883/cleanup-ff-frontend' into 'master'

Remove usage of dismissMultipleVulnerabilities feature flag in FE code

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/127549



Merged-by: Frédéric Caplette <fcaplette@gitlab.com>
Approved-by: Zamir Martins <zfilho@gitlab.com>
Approved-by: Frédéric Caplette <fcaplette@gitlab.com>
Reviewed-by: Frédéric Caplette <fcaplette@gitlab.com>
Co-authored-by: mo khan <mo@mokhan.ca>