Ruby 3.0.6

Update GitLab to Ruby 3.0.6:

https://www.ruby-lang.org/en/news/2023/03/30/ruby-3-0-6-released/

This release closes two security vulnerabilities and a few other minor bug fixes: https://github.com/ruby/ruby/releases/tag/v3_0_6

Security Fixes

    CVE-2023-28755: ReDoS vulnerability in URI
    CVE-2023-28756: ReDoS vulnerability in Time

What's Changed

    Bug #19187: Ruby 3.1.3 testsuite fails after timezone 2022g update is applied
    Rename --jit to --mjit by k0kubun · Pull Request #5248
    Merge URI-0.10.2 for Ruby 3.0 by hsbt · Pull Request #7607
    Bug #19161: Cannot compile 3.0.5 or 3.1.3 on Red Hat Enterprise Linux 7

It should be sufficient to update the following repositories:

• build images: gitlab-build-images!665 (merged)
• CNG: gitlab-org/build/CNG!1355 (merged)
• Omnibus: omnibus-gitlab!6792 (merged)

We do not need documentation updates since we do not specify patch-level Ruby versions as requirements, only minor/major.