transformers safetensors qwen2 text-generation generated_from_trainer trl dpo conversational dataset:trl-lib/ultrafeedback_binarized arxiv:2305.18290 base_model:Qwen/Qwen2.5-7B-Instruct base_model:finetune:Qwen/Qwen2.5-7B-Instruct autotrain_compatible text-generation-inference endpoints_compatible region:us