Use latest ruby versions on test job

[m-nakamura145]

This Pull Request updates the CI configuration to always use the latest stable version of Ruby.

[iliabylich]

May I ask you to wrap them with parentheses? 3.0.0 is a string in YAML and so it precisely defines the version, 3.0 becomes a float that gets "rounded" to just 3 which I assume is the latest 3.x.y version (you can check it yourself by looking at the output of 3.0 job, it's been executed with 3.3.1)

[mbj]

May I ask you to wrap them with parentheses?

I wish github would allow re-usable workflows like ruby/setup-ruby to specify type expectations in their parameters. This would avoid these kinds of footguns.

[m-nakamura145]

@iliabylich Thank you! Fixed! 6c8622a

[iliabylich]

Thanks.