wsi/x11: explicit sync

This is an implementation of explicit sync for the Vulkan X11 WSI. It makes use of common code from Joshie's explicit sync implementation for the Wayland WSI !25709 (merged).

Requirements...

• X11 protocol specifications (now available in xorgproto 2024.1): xorg/proto/xorgproto!59 (merged)
• Xwayland implementation: xorg/xserver!967 (merged)
• XCB protocol definition: xorg/proto/xcbproto!45 (merged)
• libxcb update: xorg/lib/libxcb!58 (merged)
• Wayland protocol specification (now available in wayland-protocols 1.34): wayland/wayland-protocols!90 (merged)
• kernel bug fix, otherwise vkAcquireNextImageKHR will hang (now available in Linux 6.8): https://lists.freedesktop.org/archives/dri-devel/2024-January/438275.html