NVIDIA 615.71.09 Linux Driver Features Vulkan Improvements

NVIDIA has added support for VK_NV_low_latency revision 2, to enable out-of-the-box Proton support for NVIDIA Reflex in Vulkan-native games. In addition:  Fixed a bug which prevented VK_NV_low_latency2 from reducing latency on swapchains created from VK_KHR_wayland_surface and VK_KHR_display surfaces. Fixed multiple startup and alt-tab hangs that occurred with NVIDIA Smooth Motion enabled. Fixed a bug that caused a file descriptor leak when the Vulkan loader unloads libGLX_nvidia.so.0 after a call to vkDestroyInstance. Added support for the VK_EXT_cluster_acceleration_structure Vulkan extension.