wgl: Fix non-d3d12 drivers on Windows
My bad
It's time to delete this support check. It was a stopgap before DXGI swapchains were hooked up on the D3D side I think. I don't even know. It's not useful anymore, all drivers on Windows support GDI interop and double-buffering. The driver still needs to know what was selected, since e.g. GDI support affects the d3d12 driver behavior, but it doesn't need to be filtered here.
The old code before c432fbe5 ignored the support checks for double-buffering and just always included it, which was broken from how the code looked like it was supposed to work, but turned out to be load-bearing.
Should fix #11220 (closed) /cc @zmike @jrfonseca