Add Jammy support for ruby samples

[robdimsdale]

Now that we have Jammy support for Ruby, we should ensure that all these samples work on Ruby. We should document Jammy support and we should test against Jammy in the integration tests.

We know that at least one app (the rails assets app) doesn't work on jammy - at least not out-of-the-box. See paketo-buildpacks/ruby#889 for more details.