ci/windows: Rev Vulkan SDK and piglit
The new Vulkan SDK includes https://github.com/KhronosGroup/SPIRV-Tools/commit/fb91e6f0eba66be08a5ece5ec389137762096702 in SPIRV-Tools, and the new piglit includes piglit@8a9a9acf. These removes most of the SPIRV failures - there's a few that are actual driver issues that need to be debugged.
Edited by Jesse Natalie