latest bnb no longer has optim_args attribute on optimizer

[winglian]

What does this PR do?

with latest bitsandbytes:

[rank1]:   File "/root/miniconda3/envs/py3.11/lib/python3.11/site-packages/accelerate/utils/deepspeed.py", line 53, in map_pytorch_optim_to_deepspeed                                                                                                        
[rank1]:     is_adaw = isinstance(optimizer, (bnb_opt.AdamW, bnb_opt.AdamW32bit)) and optimizer.optim_bits == 32                                                                                                                                             
[rank1]:                                                                              ^^^^^^^^^^^^^^^^^^^^                                                                                                                                                   
[rank1]: AttributeError: 'AdamW' object has no attribute 'optim_bits'                                                                                                                                                                                        

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Who can review?

@muellerzr

[winglian]

we might have to combine this with #3305 @bursteratom. I think 3305 isn't backwards compatible with older versions of bnb, but it also checks the lion optimizer case.

[BenjaminBossan]

@matthewdouglas Do you have time to check this?

[matthewdouglas]

It's not immediately clear to me what could have changed on the bnb side. With that said, this still looks like a reasonable change to me.

[muellerzr]

Thanks, if @matthewdouglas is okay with this I am as well

[HuggingFaceDocBuilderDev]

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[SunMarc]

LGTM !