Just to add to the pile-on, no real extra information, I'm having the exact same thing happening to me (stack trace looks identical), all simulators running iOS 15.4. With the 13 series simulators it can sometimes go away with a clean code rebuild but that doesn't seem to work when using the 12 series simulators. Building using Xamarin and Visual Studio for Mac rather than XCode, if that makes a difference. Running the exact same code on an iPhone 11 simulator running iOS 13.7 seems to work fine. Not sure if this is useful information but hopefully Apple can address this soon as it appears to be an issue with the simulators.

Just to add to the pile-on, it's happening for us too. Was able to deploy to an iPhone until a couple of hours ago, then got the "could not find any available provisioning profiles" error. I suspect it's because of the "Authentication Service is unavailable error" that we're all talking about. Please help Apple! Can still use simulators but I need to deploy to a real device for certain things too.