Use "customize" instead of "customise"

Author: ydah

lib/rspec/rails/matchers/have_enqueued_mail.rb

@@ -134,7 +134,7 @@ def mail_job_message(job)
         end
 
         # Ruby 3.1 changed how params were serialized on Rails 6.1
-        # so we override the active job implementation and customise it here.
+        # so we override the active job implementation and customize it here.
         def deserialize_arguments(job)
           args = super