style: apply yapf 0.31.0 formatting (CI lint fix)

- Collapse multi-line .format() call in _generate_dataset error message.
- Add blank line before 'return _side_effect' in nested function in test.

Author: Hongtao Zhang

superbench/benchmarks/model_benchmarks/megatron_gpt3.py

@@ -661,9 +661,7 @@ def _generate_dataset(self):    # noqa: C901
                         logger.error(
                             'data_prefix must end with "{}" and have a non-empty stem when '
                             'dataset generation is required (got "{}"). preprocess_data.py '
-                            'always appends "{}" to --output-prefix.'.format(
-                                suffix, self._args.data_prefix, suffix
-                            )
+                            'always appends "{}" to --output-prefix.'.format(suffix, self._args.data_prefix, suffix)
                         )
                         self._result.set_return_code(ReturnCode.DATASET_GENERATION_FAILURE)
                         return False

tests/benchmarks/model_benchmarks/test_megatron_gpt.py

@@ -203,6 +203,7 @@ def _side_effect(*_args, **_kwargs):
                     p = Path(self._tmp_dir) / f'{prefix}{ext}'
                     p.touch()
                     created_files.append(p)
+
             return _side_effect
 
         self.addCleanup(lambda: [p.unlink() for p in created_files if p.is_file()])