llama : add support for Tekken pre-tokenizer (#8579)
* llama : Added support for Tekken pre-tokenizer (#8577)
Removed uneeded `vocab.tokenizer_clean_spaces` assignment
* llama : fix order of pre-tokenizers
* * Tekken pre-tokenizer no longer uses clean_up_tokenization_spaces
* Updated chkhsh for Tekken tokenizer
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Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>
