Adding the .ruby-verison file triggered previously un-run cops, specifically:
This cop is designed to help upgrade to Ruby 3.0. It will add the
comment `# frozen_string_literal: true` to the top of files to enable
frozen string literals. Frozen string literals will be default in Ruby
3.0. The comment will be added below a shebang and encoding comment. The
frozen string literal comment is only valid in Ruby 2.3+.
More info on rubocop [Automatic-Corrections](https://github.com/bbatsov/rubocop/wiki/Automatic-Corrections)
