Make several audio datasets streamable
Reading FLAC (for `librispeech_asr`) works OK for me (`soundfile` version: `0.10.3`):
```python
In [2]: ds = load_dataset("datasets/librispeech_asr/librispeech_asr.py", "clean", streaming=True, split="train.100")

In [3]: item = next(iter(ds))

In [4]: item.keys()
Out[4]: dict_keys(['file', 'audio', 'text', 'speaker_id', 'chapter_id', 'id'])

In [5]: item["file"]
Out[5]: '374-180298-0000.flac'

In [6]: item["audio"].keys()
Out[6]: dict_keys(['path', 'array', 'sampling_rate'])

In [7]: item["audio"]["sampling_rate"]
Out[7]: 16000

In [8]: item["audio"]["path"]
Out[8]: '374-180298-0000.flac'

In [9]: item["audio"]["array"].shape
Out[9]: (232480,)
``` Oh cool ! I think this might have come from an issue with my local `soundfile` installation then I'll do `multilingual_librispeech` in a separate PR since it requires the data to be in another format (in particular separate the train/dev/test splits in different files)
<s>Needs https://github.com/huggingface/datasets/pull/3129 to be merged first</s>

Make those audio datasets streamable:
- [x] common_voice
- [x] openslr
- [x] vivos
- [x] librispeech_asr <s>(still has some issues to read FLAC)</s> *actually it's ok*
- [ ] <s>multilingual_librispeech (yet to be converted)</S> *TODO in a separate PR*