Fix error expectation tests on Rails 7.2+

Rails 7.2 changed the default for show_exceptions in tests from false
to :rescuable, causing exceptions during requests to be rescued instead
of raised. Explicitly disable exception handling in tests.

Author: tf

spec/rails_helper.rb

@@ -4,6 +4,12 @@
 require 'combustion'
 Combustion.initialize!(:active_record, :action_controller, :action_view, :sprockets)
 
+if Rails.version >= '7.1'
+  Rails.application.config.action_dispatch.show_exceptions = :none
+else
+  Rails.application.config.action_dispatch.show_exceptions = false
+end
+
 require 'rspec/rails'
 require 'support/reset_settings'