Remove useless code (#56230)
Summary:
Since we're using specific VS, we don't need to specify VC version.
In fact, the VC version is not used in CI now.
Why I make this change now?
I'm writing a robot to update the vs_install.ps1 (https://github.com/pytorch/pytorch/pull/56261/) every 2 weeks.
It will submit a PR to check if the latest VS is compatible with PyTorch automatically.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/56230
Reviewed By: bdhirsh
Differential Revision: D27856647
Pulled By: ezyang
fbshipit-source-id: b46f2bdf35ab5841fded470e23bbf7a01d5f60f4
