Crash for release build on iOS

[TheKelsam]

Trimming/Linker breaks SpriteFont loading

This can be easily reproduced by creating a new Android project (MonoGame 3.8.1.303, .NET6, Android 31), though I have the same issue with iOS. Add a new SpriteFont to your content (default Arial template is fine), and then try to build a release build (or enable the trimmer/linker on a debug build to actually see the error). It will crash when attempting to load the SpriteFont with Could not find ContentTypeReader Type I have tried to set the trim mode to SDK Only. I have tried to add a RootA…