[dataset request] Add Common Voice 12.0
### Feature request

Please add the common voice 12_0 datasets. Apart from English, a significant amount of audio-data has been added to the other minor-language datasets.

### Motivation

The dataset link:
https://commonvoice.mozilla.org/en/datasets

@polinaeterna any tentative date on when the Common Voice 12.0 dataset will be added ? This dataset is now hosted on the Hub here: https://huggingface.co/datasets/mozilla-foundation/common_voice_12_0