transformers safetensors mistral text-generation nm-vllm marlin int4 conversational arxiv:2210.17323 base_model:HuggingFaceH4/zephyr-7b-beta base_model:quantized:HuggingFaceH4/zephyr-7b-beta autotrain_compatible text-generation-inference endpoints_compatible 4-bit gptq region:us