Fix scroll handler

This weakref was not sticking around, so reverting back to a normal delegate.

Fixes #33

VirtualListView/Apple/CvDelegate.ios.maccatalyst.cs

@@ -17,7 +17,7 @@ public CvDelegate(VirtualListViewHandler handler, UICollectionView collectionVie
 	internal readonly WeakReference<UICollectionView> NativeCollectionView;
 	internal readonly VirtualListViewHandler Handler;
 
-	public WeakReference<Action<NFloat, NFloat>> ScrollHandler { get; set; }
+	public Action<NFloat, NFloat> ScrollHandler { get; set; }
 
 	public override void ItemSelected(UICollectionView collectionView, NSIndexPath indexPath)
 		=> HandleSelection(collectionView, indexPath, true);
@@ -49,8 +49,7 @@ void HandleSelection(UICollectionView collectionView, NSIndexPath indexPath, boo
 
 	public override void Scrolled(UIScrollView scrollView)
 	{
-		if (ScrollHandler?.TryGetTarget(out var handler) ?? false)
-			handler?.Invoke(scrollView.ContentOffset.X, scrollView.ContentOffset.Y);
+		ScrollHandler?.Invoke(scrollView.ContentOffset.X, scrollView.ContentOffset.Y);
 	}
 
 	public override bool ShouldSelectItem(UICollectionView collectionView, NSIndexPath indexPath)

VirtualListView/Apple/VirtualListViewHandler.ios.maccatalyst.cs

@@ -62,8 +62,7 @@ protected override void ConnectHandler(UICollectionView nativeView)
 		dataSource = new CvDataSource(this);
 
 		cvdelegate = new CvDelegate(this, nativeView);
-		cvdelegate.ScrollHandler = new WeakReference<Action<System.Runtime.InteropServices.NFloat, System.Runtime.InteropServices.NFloat>>((x, y) =>
-			VirtualView?.Scrolled(x, y));
+		cvdelegate.ScrollHandler = (x, y) => VirtualView?.Scrolled(x, y);
 
 		nativeView.DataSource = dataSource;
 		nativeView.Delegate = cvdelegate;