Gaudi: add CI

[baptistecolle]

What does this PR do?

This PR adds CI support for the Gaudi backend. It includes an integration test that starts the model "meta-llama/Llama-3.1-8B-Instruct", performs a few requests, and verifies that the outputs match the expected results.

Additional models are also supported, but running tests for all of them is quite slow, so they are not included in the CI by default. However, instructions on how to run the integration tests for all supported models have been added to the Gaudi backend README.

[baptistecolle]

I’ll wait for the Gaudi integration test CI to pass before merging anything:
https://github.com/huggingface/text-generation-inference/actions/runs/14591230970/job/40927197928?pr=3160

The previous run was green, which gives me confidence in the current changes:
https://github.com/huggingface/text-generation-inference/actions/runs/14384130453/job/40336095297

Unfortunately, it can take days to get assigned a Gaudi1 runner 😭, so I figured I could start iterating on your reviews in the meantime rather than wait for the CI to finish before requesting feedback. In any case, I’ll only merge once the Gaudi integration test passes in the CI also

[regisss]

LGTM!

We should soon have access to Gaudi2 and Gaudi3 ephemeral runners on demand, which will makes things much easier than waiting for a DL1 instance. I suggest we wait for this to be available to update and merge this PR.

[baptistecolle]

Ok, I will wait for the new runners before adding Gaudi to the CI, as indeed the DL1 runners are super unreliable

[Narsil]

LGTM