Fix tokenizer files search on HunggingFace

[maikereis]

Fix: Tokenizer File Search When Loading Models from Hugging Face

The previous implementation only searched for tokenizer files (tokenizer_config.json, tokenizer.json, and special_tokens_map.json) if the model name pointed to a local directory. This meant that when loading a model from Hugging Face, the tokenizer files were not properly searched for or loaded. As a result, the chat_template from a locally saved tokenizer would load successfully, but the same would fail for models downloaded from Hugging Face.

This fix ensures that tokenizer files are searched for both locally and on Hugging Face. Now, the chat_template and other tokenizer configurations will load correctly regardless of whether the model is loaded from a local directory or Hugging Face.

[danielhanchen]

Thanks - sorry on the delay! @Erland366 Could you help review this PR - thanks in advance :)