Add GRPO Trainer support for third-party accelerators

[ji-huazhong]

What does this PR do?

This PR makes GRPO Trainer out of the box on Ascend NPUs.

cc @qgallouedec @lewtun

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• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
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• Did you write any new necessary tests?

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[Superskyyy]

Since the vllm device patch is growing larger. It might be wise to move them into a utility module instead. Wdyt.

[baymax591]

This PR helps a lot, I hope it can speed up the integration

[ji-huazhong]

I think this PR is ready to be merged 🤗 @qgallouedec

[HuggingFaceDocBuilderDev]

The docs for this PR live here. All of your documentation changes will be reflected on that endpoint. The docs are available until 30 days after the last update.

[qgallouedec]

Can you make sure sure to run make precommit to apply the style 🙏

[ji-huazhong]

make precommit is successfully executed locally

[lynnzhiyun]

Hi @ji-huazhong, Thank you for your excellent work! This PR has been incredibly helpful in enabling me to train models using GRPO on the NPU smoothly.

I want to ask if this PR is ready to be merged and I'd be extremely grateful if it could be done promptly.

cc @qgallouedec

[qgallouedec]

this should always be the case, no?

[ji-huazhong]

Hi @qgallouedec

Thanks for your review. In line 387，I maintained the same logic as orignal conditional statement，only repalcing the 'cuda' type with more general type.

I believe the check for device availability here is necessary. However, perhaps we could split this conditional statement into two parts.

First, we check if the device type matches, and only after this condition is met do we check if the device index is within the range of available devices. wdyt?

[ji-huazhong]

I did a test on Ascend NPU using the grpo script provided by open-r1, it works 🤗

Since training grpo for one step takes a long time, only the output of the first 4 steps is shown here, and then I just press ctrl-c to exit.

[ji-huazhong]

Hi @kashif, the failing test case seems unrelated to this PR. Could you take a look? Thanks!