transformers safetensors qwen2 text-generation unsloth conversational en arxiv:2407.10671 base_model:Qwen/Qwen2.5-1.5B-Instruct base_model:finetune:Qwen/Qwen2.5-1.5B-Instruct license:apache-2.0 autotrain_compatible text-generation-inference endpoints_compatible region:us