Update tokenizer_class to LlamaTokenizerFast for GGUF compatibility

tokenizer_config.json

@@ -1,23 +1,23 @@
-{
-  "backend": "tokenizers",
-  "bos_token": "<|endoftext|>",
-  "clean_up_tokenization_spaces": false,
-  "eos_token": "<|im_end|>",
-  "extra_special_tokens": [
-    "<|im_start|>",
-    "<|im_end|>",
-    "<|tool_call|>",
-    "<|/tool_call|>",
-    "<|tool_response|>",
-    "<|begin_of_thought|>",
-    "<|end_of_thought|>",
-    "<|reserved_0|>",
-    "<|reserved_1|>"
-  ],
-  "is_local": false,
-  "local_files_only": false,
-  "model_max_length": 1000000000000000019884624838656,
-  "pad_token": "<|endoftext|>",
-  "tokenizer_class": "TokenizersBackend",
-  "unk_token": "<|endoftext|>"
-}
+{
+  "backend": "tokenizers",
+  "bos_token": "<|endoftext|>",
+  "clean_up_tokenization_spaces": false,
+  "eos_token": "<|im_end|>",
+  "extra_special_tokens": [
+    "<|im_start|>",
+    "<|im_end|>",
+    "<|tool_call|>",
+    "<|/tool_call|>",
+    "<|tool_response|>",
+    "<|begin_of_thought|>",
+    "<|end_of_thought|>",
+    "<|reserved_0|>",
+    "<|reserved_1|>"
+  ],
+  "is_local": false,
+  "local_files_only": false,
+  "model_max_length": 1000000000000000019884624838656,
+  "pad_token": "<|endoftext|>",
+  "tokenizer_class": "LlamaTokenizerFast",
+  "unk_token": "<|endoftext|>"
+}