fix: rubocop

Author: Justintime50

easypost.gemspec

@@ -29,7 +29,7 @@ Gem::Specification.new do |spec|
   spec.add_development_dependency 'ostruct', '~> 0.6'
   spec.add_development_dependency 'rdoc', '~> 6.12'
   spec.add_development_dependency 'rspec', '~> 3.13'
-  spec.add_development_dependency 'rubocop', '~> 1.72'
+  spec.add_development_dependency 'rubocop', '= 1.73'
   spec.add_development_dependency 'rubocop-rspec', '2.31' # can't upgrade to 3.0, requires easycop config changes
   spec.add_development_dependency 'simplecov', '~> 0.22'
   spec.add_development_dependency 'simplecov-lcov', '~> 0.8'