fix CI for Rails 6.1/7.0 + add support for Rails 8.1

[ashkulz]

Rails 8.1 was released on Oct 22, and CI is fully green on my fork with these changes.

Would you be interested in an automated release workflow? I've done that for gems I maintain -- see prontolabs/pronto@c7007de and I've found it helps get over the friction of making a new release 🙂

[ashkulz]

@jrafanie can please review this?

[jrafanie]

Thanks for the ping @ashkulz. This looks good. I'll merge and release.

EDIT: Just waiting on CI

[jrafanie]

@ashkulz thanks again, 4.2.0 is released...https://rubygems.org/gems/default_value_for/versions/4.2.0

I'm not opposed to automating updates but some of the machinery you had to change here would need to be updated also. Is there any automation around appraisal? I only use it here and find it a little cumbersome.

[ashkulz]

@jrafanie I personally think appraisal has become a bit redundant, it's much easier to have a Gemfile which allows overriding specific gem versions and use the matrix feature in GitHub Actions to test all combinations.

While testing with multiple Rails versions locally is something that appraisal can do, I find it much easier to just create a PR and iterate based on failing CI tests -- there's no way I'm going to install so many Ruby versions locally!

I'm happy to make a PR to migrate from appraisal => GitHub actions if you want, but I think that's orthogonal to the release workflow I mentioned above -- it just automates the release to RubyGems, so you push a tag and then a release is made in RubyGems.