Add UNI_TASK define to WebAuthComponent

The WebAuthComponent is now only included when the UNI_TASK symbol is defined, in addition to the existing Unity platform checks. This helps control compilation based on the presence of the UniTask library.

Author: Fellmonkey

templates/unity/Assets/Runtime/Core/WebAuthComponent.cs.twig

@@ -1,4 +1,4 @@
-#if UNITY_EDITOR || UNITY_IOS || UNITY_ANDROID || UNITY_WEBGL
+#if (UNITY_EDITOR || UNITY_IOS || UNITY_ANDROID || UNITY_WEBGL) && UNI_TASK
 using System;
 using System.Collections.Concurrent;
 using System.Web;