Fix Typo: belong_to updated to belongs_to

Author: akhilgkrishnan

activerecord/test/activejob/destroy_association_async_job_test.rb

@@ -39,7 +39,7 @@ class DestroyAssociationAsyncJobTest < ActiveRecord::TestCase
     assert_match %r/destroy_association_async_job: uninitialized constant PretendActiveJobIsNotPresent/, error.message
   end
 
-  test "belong_to dependent destroy_async requires destroy_association_async_job" do
+  test "belongs_to dependent destroy_async requires destroy_association_async_job" do
     error = assert_raises ActiveRecord::ConfigurationError do
       UnusedBelongsToAsync.belongs_to :essay_destroy_async, dependent: :destroy_async
     end