Correctly set hidden_feedback for inherited files

Without this fix, hidden_feedback was only effective when read_only was set, too.

app/models/code_ocean/file.rb

@@ -136,7 +136,7 @@ module CodeOcean
     end
 
     def set_ancestor_values
-      %i[feedback_message file_type hidden name path read_only role weight].each do |attribute|
+      %i[feedback_message file_type hidden name path read_only role weight hidden_feedback].each do |attribute|
         send(:"#{attribute}=", ancestor.send(attribute))
       end
     end