Ensure vendor gems child pipeline runs with gitlab-org runners

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/152527



Merged-by: Nao Hashizume <nhashizume@gitlab.com>
Approved-by: Stan Hu <stanhu@gmail.com>
Approved-by: Nao Hashizume <nhashizume@gitlab.com>
Reviewed-by: Nao Hashizume <nhashizume@gitlab.com>
Co-authored-by: Jennifer Li <jli@gitlab.com>