Remove special handling of max num tracked images as it is now part of the subsystem

Assets/Scenes/ImageTracking/ImageTracking.unity

   m_Name: 
   m_EditorClassIdentifier: 
   m_ReferenceLibrary: {fileID: 11400000, guid: c86e375d7e7430442a1104e88fa21f21, type: 2}
+  m_MaxNumberOfMovingImages: 4
   m_TrackedImagePrefab: {fileID: 3312728602301253215, guid: 5d81b097707c58e4b949537763ba4bbe,
     type: 3}
 --- !u!114 &857573726

Assets/Scenes/ImageTracking/Images/ReferenceImageLibrary.asset

   m_Enabled: 1
   m_EditorHideFlags: 0
   m_Script: {fileID: 11500000, guid: 848409ee8ba454f42a5ddff137688a27, type: 3}
-  m_Name: ReferenceImageLibrary2
+  m_Name: ReferenceImageLibrary
   m_EditorClassIdentifier: 
   m_Images:
   - {fileID: 11400000, guid: a7351be44527d304a85355f98dc6e294, type: 2}

Assets/Scenes/ImageTracking/TrackedImageInfoManager.cs

 using UnityEngine.XR.ARSubsystems;
 using UnityEngine.XR.ARFoundation;
 
-#if UNITY_IOS && !UNITY_EDITOR
-using UnityEngine.XR.ARKit;
-#endif
-
 #if UNITY_EDITOR
 using UnityEditor;
 using UnityEditor.Build;
 
         foreach (var trackedImage in eventArgs.updated)
             UpdateInfo(trackedImage);
-    }
-
-    void Update()
-    {
-#if UNITY_IOS && !UNITY_EDITOR
-        var subsystem = m_TrackedImageManager.subsystem as ARKitImageTrackingSubsystem;
-        if (subsystem != null)
-        {
-            subsystem.maximumNumberOfTrackedImages = m_TrackedImageManager.referenceLibrary.count;
-        }
-#endif
     }
 }