Test the situation with D3D12 fallback #6103
Description
As it looks like Godot can now automatically try that if Vulkan is not supported, however in the one instance that was tried in the logs it then seemed like even that failed (which is not surprising on a GPU that doesn't support Vulkan). So we need to do some testing on this, and hopefully this fallback can be either disabled or won't mess with the actual opengl fallback we would want the game to automatically try.