[iOS] Simulator should support analyzeImage

[navaronbracke]

As reported in #1225 (comment)
there is an error when trying to set up the detection model for the iOS Simulator.

We should tweak the model request for the iOS SImulator.

At first glance, we can use the useCPUOnly flag, but that flag was deprecated:
https://forums.developer.apple.com/forums/thread/696714
https://developer.apple.com/documentation/vision/vnrequest/usescpuonly

We can just no-op out of it, or figure out a workaround instead.

Perhaps setting preferBackgroundProcessing to false might help on the Simulator

[navaronbracke]

I did evaluate if preferBackgroundProcessing had any effect, but that didn't help. Since useCPUOnly is deprecated in iOS 17, I opted into just returning an unsupported operation error instead.