Use our own statically stored vs_buildtools.exe (#61372)
Summary:
We might be getting limited for our VS install requests, leading to HUD failures. This PR moves it to curl from our own S3, so we wouldn't get limited.
This PR also upgrades our vs_install to 16.8.6 from 16.8.5 as moving to S3 didn't help, but moving to the newer installer did.
The CI passes the VS install now, but fails on a build error that I don't think is relevant: https://github.com/pytorch/pytorch/pull/61372/checks?check_run_id=3013140957
Pull Request resolved: https://github.com/pytorch/pytorch/pull/61372
Reviewed By: iramazanli
Differential Revision: D29597204
Pulled By: janeyx99
fbshipit-source-id: 3eb52da308451271ea80120bbf2e511fb781b5dc
