Crash when switching between full screen VM's

Issue report requested by Discord user osy:

UTM crashed while I was quickly switching between different fullscreen VM's and other full-screen applications. I've attached the crash log below. I have not yet been able to reproduce the issue (Edit: I've reproduced it twice more, once with only a single gesture from the desktop to a fullscreen UTM running an Apple virtualization stack) and I did not have debug logging enabled at the time of the crash.

**Configuration**
* UTM Version: 4.0.9 (68)
* macOS Version: macOS 13.0 (22A380)
* Mac Chip (Intel, M1, ...): M1 Max

**Crash log**
Attached:
[UTM-2022-10-27-181934.ips.zip](https://github.com/utmapp/UTM/files/9890508/UTM-2022-10-27-181934.ips.zip)