[PoC] migrate docs workflow to GHA

[pmeier]

I don't intend to merge this PR at this point, since we need to resolve the doc preview issue on GHA first. In pytorch/test-infra#3842 @DanilBaibak enabled Dr. CI, i.e. the bot that will comment below, for torchvision again. Although it doesn't work yet, the artifact generated by the workflow added in this PR needs to be uploaded to a S3 bucket similar to what is done in PyTorch core. If I'm not mistaken, we only need to have a second job that depends on the one I added, that downloads the artifact and uploads it again to S3.

I ignored some intricacies here, like nightly doc upload and release branch version fix:

vision/.circleci/config.yml

Lines 893 to 895 in 82cf540

	# turn v1.12.0rc3 into 1.12.0
	tag=$(echo $CIRCLE_TAG | sed -e 's/v*\([0-9.]*\).*/\1/')
	VERSION=${tag:-main}

cc @seemethere

[pytorch-bot]

🔗 Helpful Links

🧪 See artifacts and rendered test results at hud.pytorch.org/pr/pytorch/vision/7407

• 📄 Preview Python docs built from this PR

Note: Links to docs will display an error until the docs builds have been completed.

This comment was automatically generated by Dr. CI and updates every 15 minutes.

[pmeier]

Jobs is green: https://github.com/pytorch/vision/actions/runs/4383643063/jobs/7674140541. Documentation is available as artifact: https://github.com/pytorch/vision/actions/runs/4383643063. I've verified that it is ok.

[malfet]

So, upload fails because you need to run the build on pytorch org runner rather than on a stock github one

[malfet]

I can see doc preview now (need to fix URL in the hud though): https://docs-preview.pytorch.org/vision/7407/index.html

[malfet]

I can see the preview, which means change is good to go: https://docs-preview.pytorch.org/vision/7407/index.html

[github-actions]

Hey @malfet!

You merged this PR, but no labels were added. The list of valid labels is available at https://github.com/pytorch/vision/blob/main/.github/process_commit.py