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
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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