Adapt tests to Rails 8.2+ re-introduction of enqueue_after_transaction_commit

See rails/rails#55788

This setting has gone through different stages, and we must account for
them:
- Rails 7.1: Method not available (no deferred enqueue)
- Rails 7.2: :default (defers to adapter's method, which returns true in
  Solid Queue's case)
- Rails 8.0-8.1: false (no deferred enqueue, the setting was deprecated)
- Rails 8.2: true (deferred enqueue enabled by default)

Author: rosa

test/integration/concurrency_controls_test.rb

@@ -178,8 +178,9 @@ class ConcurrencyControlsTest < ActiveSupport::TestCase
   end
 
   test "verify transactions remain valid after Job creation conflicts via limits_concurrency" do
-    # Doesn't work with enqueue_after_transaction_commit? true on SolidQueueAdapter, but only Rails 7.2 uses this
-    skip if Rails::VERSION::MAJOR == 7 && Rails::VERSION::MINOR == 2
+    # Doesn't work when enqueue_after_transaction_commit is enabled
+    skip if ActiveJob::Base.respond_to?(:enqueue_after_transaction_commit) &&
+            [ true, :default ].include?(ActiveJob::Base.enqueue_after_transaction_commit)
 
     ActiveRecord::Base.transaction do
       NonOverlappingUpdateResultJob.perform_later(@result, name: "A", pause: 0.2.seconds)

test/models/solid_queue/job_test.rb

@@ -340,8 +340,9 @@ class DiscardableNonOverlappingGroupedJob2 < NonOverlappingJob
   end
 
   test "enqueue successfully inside a rolled-back transaction in the app DB" do
-    # Doesn't work with enqueue_after_transaction_commit? true on SolidQueueAdapter, but only Rails 7.2 uses this
-    skip if Rails::VERSION::MAJOR == 7 && Rails::VERSION::MINOR == 2
+    # Doesn't work when enqueue_after_transaction_commit is enabled
+    skip if ActiveJob::Base.respond_to?(:enqueue_after_transaction_commit) &&
+            [ true, :default ].include?(ActiveJob::Base.enqueue_after_transaction_commit)
     assert_difference -> { SolidQueue::Job.count } do
       assert_no_difference -> { JobResult.count } do
         JobResult.transaction do