iOS Runtime duplicate error

### Help us understand the severity of this issue

- [x] breakage; unable to contribute or trigger builds will no workarounds
- [ ] inconvenient workarounds exist, but significant effort required
- [ ] needed for a Flutter team-wide priority (already agreed upon)
- [ ] nice-to-have; none of the above

### What do you need help with

In our recipes, we install Xcode and the simulator if needed. Before installing the simulator, we check to see if it's already mounted before trying to install it.

https://flutter.googlesource.com/recipes/+/refs/heads/main/recipe_modules/osx_sdk/api.py#631

https://flutter.googlesource.com/recipes/+/refs/heads/main/recipe_modules/osx_sdk/api.py#903

This seems to be not working reliably since we're getting duplicate errors:

```
D: CF3C4FF5-5955-4270-A1DB-F0911B361A8E iOS (26.0 - 23A343) (Unusable - Other Failure: Error Domain=SimDiskImageErrorDomain Code=5 "Duplicate of CEB93769-0E90-4D4E-9913-3E399AF86F24" UserInfo={NSLocalizedDescription=Duplicate of CEB93769-0E90-4D4E-9913-3E399AF86F24, unusableErrorDetail=})
```
https://ci.chromium.org/ui/p/flutter/builders/try/Mac%20Engine%20Drone/2091564/overview