Add hf_transfer dependency to fix model loading error

- Added hf_transfer>=0.1.4 to requirements.txt
- Fixes 'hf_transfer package not available' error during model download
- Required for fast downloading of large GPT-OSS-20B model files on HF Spaces

requirements.txt

@@ -5,6 +5,7 @@ accelerate>=0.25.0
 torch>=2.0.0
 bitsandbytes>=0.40.0
 huggingface_hub>=0.20.0
+hf_transfer>=0.1.4
 xformers>=0.0.20
 triton>=2.0.0
 sentencepiece>=0.1.99