Byt5
# 🌟 New model addition

## Model description
Tokenizer free Version of mt5
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## Open source status

* [X] the model implementation is available: (give details)
* https://github.com/google-research/byt5
* [X] the model weights are available: (give details)
* https://github.com/google-research/byt5
* [ ] who are the authors: (mention them, if possible by @gh-username)

hopefully getting closed by https://github.com/huggingface/transformers/pull/11971