code: def update_default(cls) -> 'TrustStoresRepository':
          
          temp_path = mkdtemp()
          try:
              # Download the latest trust stores
              archive_path = join(temp_path, 'trust_stores_as_pem.tar.gz')
              urlretrieve(cls._UPDATE_URL, archive_path)
  
              # Extract the archive
              extract_path = join(temp_path, 'extracted')
              tarfile.open(archive_path).extractall(extract_path)
  
              # Copy the files to SSLyze and overwrite the existing stores
              shutil.rmtree(cls._DEFAULT_TRUST_STORES_PATH)
              shutil.copytree(extract_path, cls._DEFAULT_TRUST_STORES_PATH)
          finally:
              shutil.rmtree(temp_path)
  
          # Re-generate the default repo - not thread-safe
          cls._DEFAULT_REPOSITORY = cls(cls._DEFAULT_TRUST_STORES_PATH)
          return cls._DEFAULT_REPOSITORY
docs: Update the default trust stores used by SSLyze.
  
          The latest stores will be downloaded from https://github.com/nabla-c0d3/trust_stores_observatory.