Update unsloth compatibility (#3970)

Co-authored-by: tastelikefeet <[email protected]>

Author: tastelikefeet

swift/cli/sft.py

@@ -1,9 +1,6 @@
 # Copyright (c) Alibaba, Inc. and its affiliates.
 import os
 
-if int(os.environ.get('UNSLOTH_PATCH_TRL', '0')) != 0:
-    import unsloth
-
 from swift.llm import sft_main
 
 if __name__ == '__main__':

swift/llm/model/register.py

@@ -142,7 +142,9 @@ def load_by_unsloth(args):
         model_name=args.adapters and args.adapters[0] or args.model_dir,
         dtype=args.torch_dtype,
         max_seq_length=args.max_length,
+        full_finetuning=args.quant_bits is None,
         load_in_4bit=args.quant_bits == 4,
+        load_in_8bit=args.quant_bits == 8,
     )
     if isinstance(model, PeftModel):
         base_model = model.model