Update Ruby version for Windows in the contribution guide

[HangJung97]

The latest version of Ruby causes issues when installing wdm on Windows machines. The version 3.1.2-1 works fine without errors.

[nathanpainchaud]

I don't see a strong reason to demand the latest version of ruby for the project. However, I'd have 2 questions to make sure simply installing a new version will work:

• When I follow the link to the download page for Ruby, I see that the version 3.1.2 is not just the version before the latest one. Did you chose it because it was the one you had on your system, so you know it would work? Because I suspect that if there are issues with the latest version (3.3.6?), maybe the latest version of a previous stable branch (e.g. 3.2.x, 3.1.x) could work? And if so, it probably is a better candidate to pin the ruby version.
• Given that the Gemfile.lock for the dependencies is checked into version control, have you tested if the lockfile still works (without requiring any modification) for the specific Ruby version?

[HangJung97]

At the installation section for Windows users, I previously wrote the latest version of Ruby. The latest version 3.3.x is no longer compatible with the dependencies of this project.

I chose this version because it is the closest version to the one I have on my PC. I have tested with Sarra, and it worked with the current Gemfile.lock without any errors.