Depend on readline-ext to get proper behavior of pry prompt

In ruby 3.3, readline falls back to reline by default. This creates odd
output when the terminal is not a real TTY. See
ruby/reline#616.

aruba.gemspec

@@ -34,6 +34,10 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency "pry", [">= 0.13.0", "< 0.15.0"]
   spec.add_development_dependency "rake", [">= 12.0", "< 14.0"]
   spec.add_development_dependency "rake-manifest", "~> 0.2.0"
+
+  # Work-around for https://github.com/ruby/reline/issues/616 in Ruby 3.3
+  spec.add_development_dependency "readline-ext", "~> 0.2.0"
+
   spec.add_development_dependency "rspec", "~> 3.11"
   spec.add_development_dependency "rubocop", ["~> 1.28", "!= 1.29.0"]
   spec.add_development_dependency "rubocop-packaging", "~> 0.5.0"