cygwin - disable VK/CUDA (#1777)
cygwin - disable VK/CUDA (#1777)

* #include an absolute path didn't work - because paths were taken to always be relative.

* Disable Vulkan and CUDA on cygwin.

Co-authored-by: Yong He <87660905d704a3fee057aaed04fb3d17ce0b45d2@outlook.com>
shader-slang/slang,csyonghe/slang,shader-slang/slang,csyonghe/slang,csyonghe/slang,shader-slang/slang