fix peft incompatible error

[wyycommu]

Due to the PEFT version not being specified, the latest version peft==0.18.0 was installed by default, causing the following error:
(as is mentioned in this issue )

  File ".venv\Lib\site-packages\peft\tuners\lora\model.py", line 26, in <module>
    from transformers.pytorch_utils import GradientCheckpointingLayer
ImportError: cannot import name 'GradientCheckpointingLayer' from 'transformers.pytorch_utils'

or

  File ".venv\Lib\site-packages\peft\tuners\lora\model.py", line 26, in <module>
    from transformers.modeling_layers import GradientCheckpointingLayer
ModuleNotFoundError: No module named 'transformers.modeling_layers'

Downgrading PEFT to version 0.15.0 resolves this issue.