Add FP8 runners + tweak building FP8 image

[zach-huggingface]

What does this PR do?

This PR adds in running TE/FP8 tests through our dedicated CI runner for said tests.

Also tweaks the docker image to allow for us to request which CUDA NVIDIA image we use (so we can get the latest TE version of the month). By default it builds with the prior month's image (so we always build off of the "latest-ish" release.

Fixes # (issue)

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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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@SunMarc @S1ro1

[SunMarc]

Thanks !

[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.

[S1ro1]

LGTM

[SunMarc]

@bot /style

[github-actions]

Style fixes have been applied. View the workflow run here.

[SunMarc]

@bot /style