[release-2.36.0][BEAM-13459] Fix sdk_container_builder too many values to unpack error (#16422)

Co-authored-by: Yichi Zhang <zyichi@google.com>

Author: emilymye

sdks/python/apache_beam/runners/portability/sdk_container_builder.py

@@ -97,7 +97,7 @@ def _prepare_dependencies(self):
       resources = Stager.extract_staging_tuple_iter(artifacts)
       # make a copy of the staged artifacts into the temp source folder.
       file_names = []
-      for path, name in resources:
+      for path, name, _ in resources:
         shutil.copyfile(path, os.path.join(self._temp_src_dir, name))
         file_names.append(name)
       with open(os.path.join(self._temp_src_dir, 'Dockerfile'), 'w') as file: