Don't write a file if there's an empty dataset

app/services/cleaner.rb

@@ -43,12 +43,14 @@ class Cleaner
           end
         end
 
+        unless data.empty?
           filename = filename(headers:, data:)
           write_csv(data: clean_csv, output_filepath:, filename:)
           write_csv(data: log_csv, output_filepath: log_filepath, prefix: "removed.", filename:)
         end
       end
     end
+  end
 
   def filename(headers:, data:)
     survey_item_ids = headers.filter(&:present?).filter do |header|