What's Changed This release candidate is focused on fixing `AutoTokenizer`, expanding the dynamic weight loading support, and improving performances with MoEs! MoEs and performances: batched and grouped experts implementations by @IlyasMoutawwakil in https://github.com/huggingface/transformers/pull/42697 Optimize MoEs for decoding using batched_mm by @IlyasMoutawwakil in https://github.com/huggingface/transformers/pull/43126 Tokenization: The main issue with the tokenization refactor is that `tokenizer_class` are now "enforced" when in most cases they are wrong. This took a while to properly isolate and now we try to use `TokenizersBackend` whenever we can.

#42894 has a much more detailed description of the big changes! use `TokenizersBackend` by @ArthurZucker in https://github.com/huggingface/transformers/pull/42894 Fix convert_tekken_tokenizer by @juliendenize in https://github.com/huggingface/transformers/pull/42592 refactor more tokenizers - v5 guide update by @itazap in https://github.com/huggingface/transformers/pull/42768 [`Tokenizers`] Change treatment of special tokens by @vasqu in https://github.com/huggingface/transformers/pull/42903 Core Here we focused on boosting…