Add new Lint/RedundantDirGlobSort cop

[koic]

Sort globbed results by default in Ruby 3.0.
https://bugs.ruby-lang.org/issues/8709

This PR adds new Lint/RedundantDirGlobSort cop.
It checks for redundant sort method to Dir.glob and Dir[].

# bad
Dir.glob('./lib/**/*.rb').sort.each do |file|
end

Dir['./lib/**/*.rb'].sort.each do |file|
end

# good
Dir.glob('./lib/**/*.rb').each do |file|
end

Dir['./lib/**/*.rb'].each do |file|
end

# good - Respect intent if `sort` keyword option is specified.
Dir.glob('./lib/**/*.rb', sort: false).each do |file|
end

Related PR #9300.

---

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• The PR relates to only one subject with a clear title and description in grammatically correct, complete sentences.
• Wrote good commit messages.
• Commit message starts with [Fix #issue-number] (if the related issue exists).
• Feature branch is up-to-date with master (if not - rebase it).
• Squashed related commits together.
• Added tests.
• Ran bundle exec rake default. It executes all tests and runs RuboCop on its own code.
• Added an entry (file) to the changelog folder named {change_type}_{change_description}.md if the new code introduces user-observable changes. See changelog entry format for details.

[bbatsov]

Nicely done!