CompositorServices framework

We're currently not binding the `CompositorServices` framework:

* It seems to be a visionOS-only framework, even though it was added to macOS in macOS 26. A few mentions in the [documentation](https://developer.apple.com/documentation/compositorservices/drawing-fully-immersive-content-using-metal?language=objc):
* "Create a fully immersive experience in visionOS [...]"
* "The result of your drawing efforts is two images, one for each eye, to create a stereosopic effect when viewed on Apple Vision Pro."
* It seems to depend on / require SwiftUI:
* "Compositor Services provides a bridge between your SwiftUI code and your Metal rendering engine code."

As such, it doesn't look like it makes much sense at the very least until we've implemented [SwiftUI support](https://github.com/dotnet/macios/issues/6235)