diffusers,hugging-face and tokenizers 0.14.1 ,they have a compatiable version

### Describe the bug

I downloaded them by pip ,and their version :huggingface-hub 0.17.3 diffusers 0.21.4
tokenizers 0.14.1 .
but when i run them, there always has an error :
Traceback (most recent call last):
File "/root/sj-tmp/migrate/echomimic-main/echomimic_api/app.py", line 34, in
from src.models.unet_2d_condition import UNet2DConditionModel
File "/root/sj-tmp/migrate/echomimic-main/src/models/unet_2d_condition.py", line 30, in
� from diffusers.utils import (
ImportError: cannot import name 'USE_PEFT_BACKEND' from 'diffusers.utils' (/root/sj-tmp/conda_envs/echomimic38/lib/python3.8/site-packages/diffusers/utils/__init__.py)

but i didn't edit the source code

### Reproduction

i have a program that uses the tool including that above

### Logs

```shell

```

### System Info

python 3.8 + conda in a docker container

### Who can help?

_No response_

Start by reproducing the import in src/models/unet_2d_condition.py with the reported Python 3.8 environment and installed versions of huggingface-hub, diffusers, and tokenizers. Compare the available diffusers.utils exports with the import of USE_PEFT_BACKEND; done means the reported application starts without this ImportError under a documented compatible dependency set.

Written by the indexing model from the issue text.