[GHA] Fix doc push jobs (#70269)
Summary:
Home folder in docker images is `/var/lib/jenkins`, rather than `/home/jenkins`
Also repo secrets can not start with `GITHUB_` prefix according to [Naming your secrets](https://docs.github.com/en/actions/security-guides/encrypted-secrets#naming-your-secrets) guide
Fixes https://github.com/pytorch/pytorch/issues/70211
Pull Request resolved: https://github.com/pytorch/pytorch/pull/70269
Reviewed By: suo
Differential Revision: D33271404
Pulled By: malfet
fbshipit-source-id: 044bb34c75a0e8a9f0b2f5790be7aa2397524a24
