Incorrect Russian filenames encoding after extraction by datasets.DownloadManager.download_and_extract()
To reproduce:

```python
>>> import datasets
>>> datasets.get_dataset_split_names('MalakhovIlya/RuREBus', config_name='raw_txt')
Traceback (most recent call last):
  File "/home/slesage/hf/datasets-preview-backend/.venv/lib/python3.9/site-packages/datasets/inspect.py", line 280, in get_dataset_config_info
    for split_generator in builder._split_generators(
  File "/home/slesage/.cache/huggingface/modules/datasets_modules/datasets/MalakhovIlya--RuREBus/21046f5f1a0cf91187d68c30918d78d934ec7113ec435e146776d4f28f12c4ed/RuREBus.py", line 101, in _split_generators
    decode_file_names(folder)
  File "/home/slesage/.cache/huggingface/modules/datasets_modules/datasets/MalakhovIlya--RuREBus/21046f5f1a0cf91187d68c30918d78d934ec7113ec435e146776d4f28f12c4ed/RuREBus.py", line 26, in decode_file_names
    for root, dirs, files in os.walk(folder, topdown=False):
  File "/home/slesage/hf/datasets-preview-backend/.venv/lib/python3.9/site-packages/datasets/streaming.py", line 66, in wrapper
    return function(*args, use_auth_token=use_auth_token, **kwargs)
TypeError: xwalk() got an unexpected keyword argument 'topdown'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/slesage/hf/datasets-preview-backend/.venv/lib/python3.9/site-packages/datasets/inspect.py", line 323, in get_dataset_split_names
    info = get_dataset_config_info(
  File "/home/slesage/hf/datasets-preview-backend/.venv/lib/python3.9/site-packages/datasets/inspect.py", line 285, in get_dataset_config_info
    raise SplitsNotFoundError("The split names could not be parsed from the dataset config.") from err
datasets.inspect.SplitsNotFoundError: The split names could not be parsed from the dataset config.
```

It's not related to the dataset viewer. Maybe @albertvillanova or @lhoestq could help more on this issue.
## Dataset viewer issue for 'MalakhovIlya/RuREBus'

**Link:** https://huggingface.co/datasets/MalakhovIlya/RuREBus

**Description**
Using os.walk(topdown=False) in DatasetBuilder causes following error:
Status code:   400
Exception:     TypeError
Message:       xwalk() got an unexpected keyword argument 'topdown'
Couldn't find where "xwalk" come from. How can I fix this?

Am I the one who added this dataset ? Yes

Incorrect Russian filenames encoding after extraction by datasets.DownloadManager.download_and_extract() 
 ## Dataset viewer issue for 'MalakhovIlya/RuREBus'

**Link:** https://huggingface.co/datasets/MalakhovIlya/RuREBus

**Description**
Using os.walk(topdown=False) in DatasetBuilder causes following error:
Status code:   400
Exception:     TypeError
Message:       xwalk() got an unexpected keyword argument 'topdown'
Couldn't find where "xwalk" come from. How can I fix this?

Am I the one who added this dataset ? Yes
 
 To reproduce:

```python
>>> import datasets
>>> datasets.get_dataset_split_names('MalakhovIlya/RuREBus', config_name='raw_txt')
Traceback (most recent call last):
  File "/home/slesage/hf/datasets-preview-backend/.venv/lib/python3.9/site-packages/datasets/inspect.py", line 280, in get_dataset_config_info
    for split_generator in builder._split_generators(
  File "/home/slesage/.cache/huggingface/modules/datasets_modules/datasets/MalakhovIlya--RuREBus/21046f5f1a0cf91187d68c30918d78d934ec7113ec435e146776d4f28f12c4ed/RuREBus.py", line 101, in _split_generators
    decode_file_names(folder)
  File "/home/slesage/.cache/huggingface/modules/datasets_modules/datasets/MalakhovIlya--RuREBus/21046f5f1a0cf91187d68c30918d78d934ec7113ec435e146776d4f28f12c4ed/RuREBus.py", line 26, in decode_file_names
    for root, dirs, files in os.walk(folder, topdown=False):
  File "/home/slesage/hf/datasets-preview-backend/.venv/lib/python3.9/site-packages/datasets/streaming.py", line 66, in wrapper
    return function(*args, use_auth_token=use_auth_token, **kwargs)
TypeError: xwalk() got an unexpected keyword argument 'topdown'

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/home/slesage/hf/datasets-preview-backend/.venv/lib/python3.9/site-packages/datasets/inspect.py", line 323, in get_dataset_split_names
    info = get_dataset_config_info(
  File "/home/slesage/hf/datasets-preview-backend/.venv/lib/python3.9/site-packages/datasets/inspect.py", line 285, in get_dataset_config_info
    raise SplitsNotFoundError("The split names could not be parsed from the dataset config.") from err
datasets.inspect.SplitsNotFoundError: The split names could not be parsed from the dataset config.
```

It's not related to the dataset viewer. Maybe @albertvillanova or @lhoestq could help more on this issue.