Fix RuboCop complaints

1 job for main in 7 minutes and 52 seconds (queued for 3 seconds)
Name Stage Failure
rubocop Test
config/application.rb:12:3: C: Style/Documentation: Missing top-level class documentation comment.
class Application < Rails::Application
test/test_helper.rb:7:7: C: Style/ClassAndModuleChildren: Use nested module/class definitions instead of compact style.
class ActiveSupport::TestCase

41 files inspected, 8 offenses detected
ERROR: Job failed: exit code 1