Migrate CI to GitHub Actions, add testing for Rails 7.0 and Ruby 3.1

[aried3r]

Test on push and pull request events and perhaps once every month to find deprecations early. See also #32 which added redis deprecation warnings as errors.

Also add Rails 7 and Ruby 3.1 to CI.

[benlangfeld]

@aried3r I'd appreciate if you would enable GH actions for #34 or give me sufficient permissions to do so myself.

[garettarrowood]

I have write access to modis, but I do not have the ability to enable Github actions nor give you more permissions to do so @benlangfeld . I would be in favor merging your additions and granting you that access level though.

[benlangfeld]

@aried3r Can we make all of these write permission? https://github.com/orgs/rpush/teams/maintainers/repositories

Might you also nominate someone else to Core and give that team admin on modis (consistent with the other repos)?

[benlangfeld]

@aried3r @ileitch I'm unable to make progress without your help with permissions.

[ileitch]

Ive added you to Core and fixed the permissions. Thank you for continuing to work on these projects 🙌