Restore Vulkan tests to periodic (#101026)
The flaky issue has been fixed by https://github.com/pytorch/pytorch/pull/100909. In addition, retry support for C++ is now available after https://github.com/pytorch/pytorch/pull/99956. So it's safe to move this back from unstable now.
Per the discussion with @clee2000, it makes sense to have this as a periodic job given that this one rarely fails. To prevent any gap here, I have created https://github.com/pytorch/test-infra/pull/4144 to add the necessary testing for Vulkan change.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/101026
Approved by: https://github.com/kit1980
