Fix GPTQ CI

[IlyasMoutawwakil]

What does this PR do?

Fixes failures from the non reproducibility and non determinism (or lack of deterministic kernels when activated) by checking expected perplexity instead of specific outputs.

Before submitting

• This PR fixes a typo or improves the docs (you can dismiss the other checks if that's the case).
• Did you make sure to update the documentation with your changes?
• Did you write any new necessary tests?

Who can review?

[IlyasMoutawwakil]

all failures are generation correctness checks that pass locally on an A100, some outputs on t4 are very bad like Hello my name is A.I.I.I.I.

[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.

[fxmarty]

LGTM as long as it passes. Thank you for fixing