This fixes two issues happening with hybrid graphics laptops.
- One is a left-over cursor that has trouble freeing itself if the dGPU got deactivated.
This one is fixed by invalidating (i.e. clearing) GPU data in the cursor renderer when a GPU is deactivated.
- The other is a page flip callback from the dGPU getting invoked after the dGPU got deactivated.
This one is fixed by delaying the deactivation until the page flip callback has been invoked.