bug: Huggingface doesn't use subproviders as URLs anymore

[joshua-mo-143]

Huggingface's subproviders don't exist anymore so we can safely get rid of them.

Follow-up from #985

[linear[bot]]

RIG-1017

[rabolon]

Dear Joshua, thank you for your quick response.

[hadronzoo]

I was just debugging this issue and this fixes it, thanks! The replace was producing invalid URLs like https:/router.huggingface.co/cerebras/v1/chat/completions.

[hadronzoo]

Note: it looks like that replace pattern is used for other providers. I would expect those URLs to also be invalid.