Add Rails supported Ruby versions on CI and update appraisals

[berkos]

👋 Thanks for the review in advance.

• Adds Rails supported Ruby versions including 3.3 in the CI matrix.
• It also updates the appraisals to update Nokogiri as on Ruby 3.3
  the current version on *.lock files was failing as below:

nokogiri-1.15.4-x86_64-linux requires ruby version < 3.3.dev, >= 2.7, which is
incompatible with the current version, 3.3.0

[djmb]

That's a lot of checks now since we have the three databases to test against. There are a few flaky tests so this will be a good push to iron those out 😅

@berkos - there are some merge conflicts now. If you could resolve them I'll merge this in

[berkos]

That's a lot of checks now since we have the three databases to test against. There are a few flaky tests so this will be a good push to iron those out 😅

@berkos - there are some merge conflicts now. If you could resolve them I'll merge this in

@djmb Sorry for the delay, conflicts have now been resolved. 🙂