set model merge dtype based on cfg

scripts/finetune.py

@@ -158,7 +158,8 @@ def check_not_in(list1: List[str], list2: Union[Dict[str, Any], List[str]]) -> b
 def merge_lora(model, tokenizer, cfg):
     LOG.info("running merge of LoRA with base model")
     model = model.merge_and_unload()
-    model.to(dtype=torch.float16)
+    model_dtype = torch.bfloat16 if cfg.bf16 or cfg.bfloat16 else torch.float16
+    model.to(dtype=model_dtype)
     if cfg.hub_model_id:
         model.push_to_hub("hub_model_id")