Once we start work on having flutter run and flutter build support visionOS devices, we should also support native assets for visionOS.

Tracking bug for flutter run and flutter build:

• Support visionOS devices for iOS apps in flutter devices, flutter run, etc. #129638

Prerequisites upstream for native assets:

• Support visionOS dart-lang/native#961

We can't really start working for support on visionOS for native assets before flutter run and flutter build can target visionOS.

I'm happy to work on this once the prerequisite work has been done.