vulkan: fix macos build
The VulkanSDK can be downloaded from LunarG website and can be installed properly in /usr/local following:
https://vulkan.lunarg.com/doc/view/latest/mac/getting_started.html
Fixes partly #2372
The VulkanSDK can be downloaded from LunarG website and can be installed properly in /usr/local following:
https://vulkan.lunarg.com/doc/view/latest/mac/getting_started.html
Fixes partly #2372