fix(ruby): accept both "_" and "." tag separators from ruby/ruby

[rhiroe]

ruby/ruby switched its release tag separator from "_" (e.g. v3_4_9) to "." (e.g. v4.0.4) starting at Ruby 4.0.0. The current regex in find_version_from_git_tags only matches the "_" form, so VERSION=latest and ADDITIONAL_VERSIONS resolution silently skip every 4.x release.

Normalize the tag list with tr "_" "." before matching and use "." canonically in the regex. The separator parameter is no longer consulted for matching, so drop the now-redundant "_" argument from the three ruby call sites.

[rhiroe]

@microsoft-github-policy-service agree

[Kaniska244]

Hi @rhiroe

Thank you for the contribution. Would you kindly bump the feature version and also add relevant test cases if applicable for this change. Also please check the failing tests.

[rhiroe]

The CI failure is caused by RVM's stable branch not including Ruby 4.x in its known rubies list (it currently tops out at ruby-3.0.0). Ruby 4.x is already present in RVM's master branch but has not yet been merged into stable.

Because install.sh uses curl -sSL https://get.rvm.io | bash -s stable, the installed RVM does not recognize 4.0.4 as a known MRI ruby. As a result, the default alias is created as 4.0.4 instead of ruby-4.0.4, producing a dangling symlink at /usr/local/rvm/rubies/default. This causes which gem to return nothing, and ${ROOT_GEM} install rake expands to install rake — invoking the system install command instead of gem install.

I'm not sure what the best path forward is here. A few options come to mind:

• Add rvm use default — resolves the issue immediately, though this doesn't address the underlying cause.
• Wait for RVM's stable branch to include Ruby 4.x — would address the root cause, though the timeline depends on the RVM project.
• Switch from stable to master in the RVM install command — would bring in Ruby 4.x support now, though it's worth considering whether using master is appropriate for this environment.

Happy to hear any thoughts on which direction makes sense.