The recommendation is now to leave `d3d12` to its default `yes` value,
which means installing Direct3D 12 dependencies is considered required
by default.
You can still skip the dependencies by compiling with `d3d12=no`, which matches
the behavior of self-compiled builds prior to Godot 4.6.
This also removes an outdated FAQ question, since a lot of time has passed
since that question was written (Godot only had Vulkan and OpenGL support
back then).
