This ticket to manage a refactoring tasks of the following ruby/* projects.

I applied the GitHub Actions ppc64le/s390x to the projects that we planned initially.

Now I want to apply some better changes that I learned during the process, into the some ruby/* repositories.

The changes are below. The PR <https://github.com/ruby/openssl/pull/946> is already applying the changes.

• Use YAML anchors and aliases feature to avoid duplicated logic between the main job and ibm (ppc64le/s390x) jobs. - <https://docs.github.com/en/actions/reference/workflows-and-actions/reusing-workflow-configurations#yaml-anchors-and-aliases>
• Use the `$(nproc)` instead of the hardcorded `2` for the `bundle install --jobs 2`.

The goal of this ticket is to apply the changes to the following repositories.

• ruby/ruby
• ruby/fiddle
• ruby/prism
• ruby/psych
• ruby/zlib