Deprecate Beam API and download from HF GCS bucket
Deprecate the Beam API and download from the HF GCS bucked. 

TODO:
- [ ] Deprecate the Beam-based [`wikipedia`](https://huggingface.co/datasets/wikipedia) in favor of [`wikimedia/wikipedia`](https://huggingface.co/datasets/wikimedia/wikipedia) ([Hub PR](https://huggingface.co/datasets/wikipedia/discussions/19))
- [ ] Make [`natural_questions`](https://huggingface.co/datasets/natural_questions) a no-code dataset ([Hub PR](https://huggingface.co/datasets/natural_questions/discussions/7))
- [ ] Make [`wiki40b`](https://huggingface.co/datasets/wiki40b) a no-code dataset ([Hub PR](https://huggingface.co/datasets/wiki40b/discussions/5))
- [ ] Make [`wiki_dpr`](https://huggingface.co/datasets/wiki_dpr) an Arrow-based dataset