Bump ruby version minimum to 2.7

[mjankowski]

Context: standardrb/standard#657

This one might need some followup re: dependency bumps and bundling. Was hitting some oddities locally with it wanting to version bump more than I wanted into this PR. Not sure if that's unique to my local setup (running just-released 3.3.6) or something that will show up on CI. Will review as followup if CI has issues.

[koic]

Although not yet implemented, there may be plans to introduce lint_roller into RuboCop in the future. This would improve compatibility across Standard and custom RuboCop gems (e.g., standard-rails, rubocop-rails, ...) by unifying the plugin interface.

Currently, RuboCop supports Ruby 2.7 and above, with no plans to drop support currently, in consideration of user convenience.

For this reason, it would be appreciated if lint_roller, as a low-level middleware, could take into account support for a broad range of Ruby versions. Personally, retroactive support for older Ruby versions is not necessary, and maintaining the current required_ruby_version (or, at least Ruby 2.7) would be sufficient.

Cc @searls

[searls]

Thanks @koic! I'll be honest, Rubocop had historically been so aggressive about dropping old Rubies that I had simply assumed you'd already dropped 2.7.

That being the case, I think at a minimum this should retain compatibility with Rubocop and we may even want to keep all the standard libraries on the same cadence as the Rubocop one

[koic]

@searls Thank you for the prompt response! Since there is incompatibility between Ruby 2.7 and 3.0, and the current stable version of Rails 7.1 still supports Ruby 2.7, RuboCop plans to continue supporting Ruby 2.7 for the time being.
https://rubygems.org/gems/rails/versions/7.1.0

Unfortunately, I see some projects still using Ruby 2.7, and I think it’s practical for RuboCop to support this version. Although no strict timeline has been set for RuboCop, I think it’s reasonable to continue supporting Ruby 2.7 for some time even after Rails 7.1 reaches EOL.

[mjankowski]

Updated the PR description and changes here to be a bump to 2.7 instead of 3.0

Also bumped the parser version, which seemed required for me locally to get things passing on 3.3. Will watch CI.

[mjankowski]

CI run here had issues on the 2.7 run - https://github.com/standardrb/lint_roller/actions/runs/11706882078 - I believe because I also bumped bundler (to a version that dropped ruby 2.7 support) itself alongside the parser bump. Just pushed again to roll bundler back but keep the parser bump.

[searls]

Thanks!

[koic]

Thank you for considering it!