Update iOS project to target ARM64 (universal is no longer allowed)

ProjectSettings/ProjectSettings.asset

     25: UNITY_POST_PROCESSING_STACK_V2
     26: UNITY_POST_PROCESSING_STACK_V2
     27: UNITY_POST_PROCESSING_STACK_V2
-  platformArchitecture: {}
+  platformArchitecture:
+    iOS: 1
   scriptingBackend: {}
   il2cppCompilerConfiguration: {}
   incrementalIl2cppBuild: {}