command-r : add BPE pre-tokenization (#7063)

* Add BPE pre-tokenization for Command-R/R+.

* Bump transformers convert requirement.

* command-r : add individual digits regex

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Co-authored-by: Georgi Gerganov <ggerganov@gmail.com>

convert-hf-to-gguf.py

@@ -311,6 +311,9 @@ class Model(ABC):
         if chkhsh == "6221ad2852e85ce96f791f476e0b390cf9b474c9e3d1362f53a24a06dc8220ff":
             # ref: https://huggingface.co/smallcloudai/Refact-1_6-base
             res = "refact"
+        if chkhsh == "9c2227e4dd922002fb81bde4fc02b0483ca4f12911410dee2255e4987644e3f8":
+            # ref: https://huggingface.co/CohereForAI/c4ai-command-r-v01
+            res = "command-r"
 
         if res is None:
             logger.warning("\n")