The column type itself is only a uuid in certain database
implementations like PostgreSQL

MySQL uuids are supportable using the Rails 5 Attributes API and
registering a new :uuid type. The column type is not a :uuid, but the
registered attribute type is a :uuid

e.g.

module ActiveRecord
  module Type
    class Uuid < ActiveRecord::Type::Binary
      def type
        :uuid
      end

      ...
    end
  end
end

ActiveRecord::Type.register(:uuid, ActiveRecord::Type::Uuid, adapter: :mysql2)

class Model < ApplicationRecord
  attribute :id, :uuid
end

Model.attribute_types[:id].type # => :uuid

Linting changes