docs yml file enable install_libgl flag

[mishig25]

@natolambert doc-build action was failing because doc-builder image didn't have libGL, which is a pyvista dependency

ImportError: libGL.so.1: cannot open shared object file: No such file or directory

Therefore, I've added libgl to the image huggingface/doc-builder#294

Docs are building (you cah check at: https://moon-ci-docs.huggingface.co/docs/simenv/pr_202/) & everything is working except:
"Add doc comment" step , which is failing because it is a private repo.
@LysandreJik could you solve the issue as you have solved for api-inference here?

[natolambert]

Thanks so much, this would've taken me a while :).
For what it is worth, we will be making it public in a couple weeks, so we could also just wait if that final step is a lot of work.

[HuggingFaceDocBuilder]

The docs for this PR live here. All of your documentation changes will be reflected on that endpoint.

[natolambert]

Merging this @mishig25, we made the library public 🤗.