peft safetensors gptj alignment-handbook trl dpo generated_from_trainer dataset:hugodk-sch/aftonposten_title_prefs base_model:NbAiLab/nb-gpt-j-6B-v2 base_model:adapter:NbAiLab/nb-gpt-j-6B-v2 4-bit bitsandbytes region:us