Fix tokenizer compatibility with newer transformers versions

Issue: A community member reported the error: "Exception: data did not match any variant of untagged enum PyPreTokenizerTypeWrapper at line 88 column 3" when trying to load the model with newer versions of the transformers library.

Root cause: The field prepend_scheme: "always" is deprecated and not recognized by the Rust tokenizers backend in newer library versions.

Solution: Updated tokenizer.json to resolve compatibility issues with recent versions of the tokenizers library.

Changes:
Line 84: Changed "prepend_scheme": "always" to "add_prefix_space": true in pre_tokenizer
Line 167: Changed "prepend_scheme": "always" to "add_prefix_space": true in decoder

tokenizer.json

@@ -1,3 +1,3 @@
 version https://git-lfs.github.com/spec/v1
-oid sha256:ac9bd80d04d21b4df95917bdf7c750cbea28acc30a4462c76ca2b9c86d371863
-size 16316225
+oid sha256:687a450aae900a541fd7c85890b174af4bbe6351ca3dbfeb9f3964e57b9401c1
+size 16316221