Add Ruby 3 support for CustomersDot images (!647) · Merge requests · GitLab.org / gitlab-build-images · GitLab

What does this MR do and why?

Add Ruby 3 support for CustomersDot images.

Checklist

(If applicable) Add patches if required for upgrading Ruby version in https://gitlab.com/gitlab-org/gitlab-build-images/-/tree/master/patches/ruby.