Valve Implements Opt-In VK_KHR_present_wait For Mesa Vulkan Drivers

Landing this week within Mesa 23.0 is an initial implementation of Vulkan's VK_KHR_present_wait extension, which Hans-Kristian Arntzen of Valve's Linux team and VKD3D-Proton notoriety has referred to as a "very useful" extension but due to current spec limitations is for now only being made opt-in via a DriConf option so it can be handled on a per-game/app basis...