Fix build errors when using UIKit for Mac (Catalyst)

Classes/GlobalStateExplorers/SystemLog/ActivityStreamAPI.h

@@ -24,11 +24,13 @@
  *
  * See <os/object.h> for details.
  */
+#if !TARGET_OS_MACCATALYST
 #if OS_OBJECT_USE_OBJC
 OS_OBJECT_DECL(xpc_object);
 #else
 typedef void * xpc_object_t;
-#endif 
+#endif
+#endif
 
 #define OS_ACTIVITY_MAX_CALLSTACK 32