code: def get_archives_to_prune(archives, hook_data):
      
      files_to_skip = []
      for i in ['current_archive_filename', 'old_archive_filename']:
          if hook_data.get(i):
              files_to_skip.append(hook_data[i])
      archives.sort(key=itemgetter('LastModified'),
                    reverse=False)  # sort from oldest to newest
      # Drop all but last 15 files
      return [i['Key'] for i in archives[:-15] if i['Key'] not in files_to_skip]
docs: Return list of keys to delete.