Changed condition for readbility

- Refactored check if item is not audio book or book to be more readable

Emby.Server.Implementations/Library/UserDataManager.cs

@@ -220,7 +220,7 @@ namespace Emby.Server.Implementations.Library
             var hasRuntime = runtimeTicks > 0;
 
             // If a position has been reported, and if we know the duration
-            if (positionTicks > 0 && hasRuntime && !(item is AudioBook) && !(item is Book))
+            if (positionTicks > 0 && hasRuntime && item is not AudioBook && item is not Book)
             {
                 var pctIn = decimal.Divide(positionTicks, runtimeTicks) * 100;