`wikipedia` pre-processed datasets
## Describe the bug
[Wikipedia](https://huggingface.co/datasets/wikipedia) dataset readme says that certain subsets are preprocessed. However it seems like they are not available. When I try to load them it takes a really long time, and it seems like it's processing them.

## Steps to reproduce the bug
```python
from datasets import load_dataset

load_dataset("wikipedia", "20220301.en")
```

## Expected results
To load the dataset

## Actual results
Takes a very long time to load (after downloading)

After `Downloading data files: 100%`. It takes hours and gets killed.
Tried `wikipedia.simple` and it got processed after ~30mins.