Destroy recurring execution when deleting a job

For example, if we don't keep finished jobs around.

Author: rosa

app/models/solid_queue/job.rb

@@ -2,7 +2,7 @@
 
 module SolidQueue
   class Job < Record
-    include Executable, Recurrable, Clearable
+    include Executable, Clearable, Recurrable
 
     serialize :arguments, coder: JSON
 

app/models/solid_queue/job/recurrable.rb

@@ -6,13 +6,8 @@ module Recurrable
       extend ActiveSupport::Concern
 
       included do
-        has_one :recurring_execution
+        has_one :recurring_execution, dependent: :destroy
       end
-
-      private
-        def execution
-          super || recurring_execution
-        end
     end
   end
 end