Update Ruby to 3.1.5

What does this MR do?

This fixes a number of CVEs and bugs:

• https://www.ruby-lang.org/en/news/2024/04/23/ruby-3-1-5-released/
• https://www.ruby-lang.org/en/news/2024/04/23/ruby-3-2-4-released/

This drops the fix-ruby-xfree-for-libxml2 patch for Ruby 3.1.5 since the change has been merged upstream.

This will also enable us to update to Puma 6.4.2 since https://bugs.ruby-lang.org/issues/19837 has been resolved in Ruby 3.1.5.

Due to https://bugs.ruby-lang.org/issues/20451, Ruby 3.1.5 does not compile on systems with libffi < 3.2 (such as UBI-8). This patch pulls in https://github.com/ruby/ruby/pull/10696.

Related issues

Omnibus MR: gitlab-org/omnibus-gitlab!7591 (merged)

Checklist

See Definition of done.

For anything in this list which will not be completed, please provide a reason in the MR discussion

Required

• Merge Request Title, and Description are up to date, accurate, and descriptive
• MR targeting the appropriate branch
• MR has a green pipeline on GitLab.com
• When ready for review, MR is labeled "~workflow::ready for review" per the Distribution MR workflow

Expected (please provide an explanation if not completing)

• Test plan indicating conditions for success has been posted and passes
• Documentation created/updated
• Integration tests added to GitLab QA
• The impact any change in container size has should be evaluated
• New dependencies are managed with dependencies.io