zink: Enable GL_EXT_depth_bounds_test

Merged Adam Jackson requested to merge ajax/mesa:zink-gl-ext-depth-bounds-test into master

Required by Vulkan 1.0, and in fact already wired up, just not advertised. It looks like we could make this dynamic state but this works for now.

Tested on NVIDIA, passes the appropriate piglits. Not sure if it'll pass against lavapipe, let's see what CI says.

Merge request reports