RuboCop: Tweaking cop rules per Ruby version

What does this MR do and why?

• Disable Lint/RedundantRequireStatement for Ruby 3.2
• Skip short-hand syntax for Style/HashSyntax for Ruby 3.2

Follow-up of !132439 (merged).

How to set up and validate locally

unset REVEAL_RUBOCOP_TODO
asdf local ruby 3.0.5

bundle exec rubocop app/model/compare.rb # Based on https://gitlab.com/gitlab-org/gitlab/-/jobs/4638615454
Inspecting 1 file
.

1 file inspected, no offenses detected

asdf local ruby 3.1.4

bundle exec rubocop app/models/compare.rb
Inspecting 1 file
.

1 file inspected, no offenses detected

asdf local ruby 3.2.2
bundle exec rubocop app/models/compare.rb

Inspecting 1 file
.

1 file inspected, no offenses detected

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.