Auto-reshim is broken when using the asdf-alias plugin

I found an interesting asdf edge case I'm not sure how to solve. It's related to the asdf-alias plugin and the auto-reshimming feature of some language plugins like Ruby.

The problem: [this hook](https://github.com/asdf-vm/asdf-ruby/blob/master/rubygems-plugin/rubygems_plugin.rb) uses the Ruby constant `RUBY_VERSION`, and when the active Ruby version is an alias version (which is a symlink to a concrete version), this results in an incorrect reshim command. For example, when the active version is `3.2`, the executed command is `asdf reshim 3.2.0` instead of `asdf reshim 3.2`.

Does anyone have a clever idea to work around this from the asdf-ruby side? One option would be to relax the reshim command to reshim all known Ruby versions, but that would be bad for performance.