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This also removes an outdated FAQ question, since a lot of time has passed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).
This follows the documentation writing guidelines, specifically
the "When to refer to a specific Godot version" section.
This also removes warning blocks for a known issue that was resolved in Godot 4.5.
Once the issue is resolved, it could support Compatibility but not
Forward+/Mobile due to these renderers requiring a feature the iOS
simulator doesn't support (image cube arrays).
