FIX: use the new duration attribute in set_or_create_timer method.

New `duration` attribute is introduced for the `set_or_create_timer` method in the commit aad12822b7d7c9c6ecd976e23d3a83626c052dce for "based on last post" and "auto delete replies" topic timers.

spec/components/post_creator_spec.rb

@@ -367,7 +367,8 @@ describe PostCreator do
             Fabricate(:topic_timer,
               based_on_last_post: true,
               execute_at: Time.zone.now - 12.hours,
-              created_at: Time.zone.now - 24.hours
+              created_at: Time.zone.now - 24.hours,
+              duration: 12
             )
           end