Add compatibility for have_enqueued_mail (rails 7)

1. ActionMailer::DeliveryJob does not exist anymore
2. ActionMailer::Parameterized::DeliveryJob

According to my research they have both been superseeded by ActionMailer::MailDeliveryJob

Closes #2531

Author: mhenrixon

lib/rspec/rails/feature_check.rb

@@ -28,13 +28,17 @@ def has_action_cable_testing?
       end
 
       def has_action_mailer_parameterized?
-        has_action_mailer? && defined?(::ActionMailer::Parameterized)
+        has_action_mailer? && defined?(::ActionMailer::Parameterized::DeliveryJob)
       end
 
       def has_action_mailer_unified_delivery?
         has_action_mailer? && defined?(::ActionMailer::MailDeliveryJob)
       end
 
+      def has_action_mailer_legacy_delivery_job?
+        defined?(ActionMailer::DeliveryJob)
+      end
+
       def has_action_mailbox?
         defined?(::ActionMailbox)
       end

lib/rspec/rails/matchers/have_enqueued_mail.rb

@@ -143,7 +143,7 @@ def mail_job_message(job)
         end
 
         def legacy_mail?(job)
-          job[:job] <= ActionMailer::DeliveryJob
+          RSpec::Rails::FeatureCheck.has_action_mailer_legacy_delivery_job? && job[:job] <= ActionMailer::DeliveryJob
         end
 
         def parameterized_mail?(job)

spec/rspec/rails/matchers/have_enqueued_mail_spec.rb

@@ -22,7 +22,12 @@ def test_email; end
       def email_with_args(arg1, arg2); end
     end
 
-    class DeliveryJobSubClass < ActionMailer::DeliveryJob
+    if RSpec::Rails::FeatureCheck.has_action_mailer_legacy_delivery_job?
+      class DeliveryJobSubClass < ActionMailer::DeliveryJob
+      end
+    else
+      class DeliveryJobSubClass < ActionMailer::MailDeliveryJob
+      end
     end
 
     class UnifiedMailerWithDeliveryJobSubClass < ActionMailer::Base