Set `library_name='dataset-viewer'` in hfh requests
See https://github.com/huggingface/dataset-viewer/pull/2788/files#diff-45fde89a57a9a9a207231137c66a1ddf75b5830ba0eb7f504f87d87f921afb27R902

```python
  headers = build_hf_headers(token=self.hf_token, library_name="dataset-viewer")
```
Set `library_name='dataset-viewer'` in hfh requests: See https://github.com/huggingface/dataset-viewer/pull/2788/files#diff-45fde89a57a9a9a207231137c66a1ddf75b5830ba0eb7f504f87d87f921afb27R902

```python
  headers = build_hf_headers(token=self.hf_token, library_name="dataset-viewer")
```