switch to RuboCop 1.30

Once in a while, keep up with RuboCop updates.
1.0 was released in 2020-10
1.30 in 2022-05

1.14 is the first one to support Ruby 3.1
but that would drop Ruby 2.4
1.30 is significant in reintroducing Ruby 2.4

2.4 is way old, but SUSE SLE 15 does keep using 2.5

Author: mvidner

.rubocop.yml

@@ -1,5 +1,8 @@
+inherit_from: .rubocop_todo.yml
+
 AllCops:
   TargetRubyVersion: 2.4
+  NewCops: enable
   Exclude:
     # Do not check code borrowed from ActiveSupport
     - 'lib/dbus/core_ext/**/*.rb'

.rubocop_todo.yml

@@ -34,7 +34,7 @@ GEMSPEC = Gem::Specification.new do |s|
   s.add_development_dependency "packaging_rake_tasks"
   s.add_development_dependency "rake"
   s.add_development_dependency "rspec", "~> 3"
-  s.add_development_dependency "rubocop", "= 1.0"
+  s.add_development_dependency "rubocop", "= 1.30"
   s.add_development_dependency "simplecov"
   s.add_development_dependency "simplecov-lcov"
 end