fix: Gemfile to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-RUBY-RACK-10074187
- https://snyk.io/vuln/SNYK-RUBY-RACK-10074188

Author: snyk-bot

Gemfile

@@ -14,7 +14,7 @@ end
 
 group :development do
   gem 'listen', '>= 3.0.5', '< 3.2'
-  gem 'i18n_generators', '2.1.1'
+  gem 'i18n_generators', '2.2.0'
   gem 'better_errors'
   gem 'web-console', '~> 3.6'
   gem 'binding_of_caller'