Remove ActiveSupport usage delegate

[Bhacaz]

If activesupport is not loaded, running AggregateExamples may cause problem since it was using delegate from activesupport.

The delegate version was automaticly changed by Rubocop with a Rails cop (which I disabled in this PR)

Orignal version: https://github.com/test-prof/test-prof/blob/02d8f355c158fb021e58ff1327d624a8299762b6/lib/test_prof/cops/rspec/language.rb#L26-L28

❯ be rubocop
undefined method `delegate' for RuboCop::Cop::RSpec::AggregateExamples::Language::SelectorSet:Class
Did you mean?  DelegateClass
/Users/jfbastien/.rbenv/versions/2.7.8/lib/ruby/gems/2.7.0/gems/rubocop-petal-1.3.0/lib/rubocop/cop/rspec/aggregate_examples/language.rb:27:in `<class:SelectorSet>'
/Users/jfbastien/.rbenv/versions/2.7.8/lib/ruby/gems/2.7.0/gems/rubocop-petal-1.3.0/lib/rubocop/cop/rspec/aggregate_examples/language.rb:14:in `<module:Language>'