fix: Avoid deflating layout slot rect by border thickness twice

Author: MartinZikmund

src/Uno.UI/UI/Xaml/Controls/CalendarView/CalendarViewBaseItemChrome.cs

@@ -1025,7 +1025,7 @@ internal void InvalidateRender()
 			//}
 		}
 
-		private Thickness GetItemBorderThickness()
+		internal Thickness GetItemBorderThickness()
 		{
 			var pOwner = GetOwner();
 			if (pOwner is { })

src/Uno.UI/UI/Xaml/FrameworkElementExtensions.cs

@@ -368,6 +368,12 @@ internal static bool TryGetBorderThickness(this IFrameworkElement frameworkEleme
 				return true;
 			}
 
+			if (__LinkerHints.Is_Windows_UI_Xaml_Controls_CalendarViewBaseItem_Available && frameworkElement is CalendarViewBaseItem cbi)
+			{
+				borderThickness = cbi.GetItemBorderThickness();
+				return true;
+			}
+
 			borderThickness = default;
 			return false;
 		}

src/Uno.UI/UI/Xaml/UIElement.skia.cs

@@ -270,10 +270,7 @@ partial void OnRenderTransformSet()
 
 		internal void ArrangeVisual(Rect finalRect, Rect? clippedFrame = default)
 		{
-			LayoutSlotWithMarginsAndAlignments =
-				VisualTreeHelper.GetParent(this) is UIElement parent and not RootVisual
-					? finalRect.DeflateBy(parent.GetBorderThickness())
-					: finalRect;
+			LayoutSlotWithMarginsAndAlignments = finalRect;
 
 			var oldFinalRect = _currentFinalRect;
 			_currentFinalRect = finalRect;

src/Uno.UI/UI/Xaml/UIElement.wasm.cs

@@ -219,10 +219,7 @@ protected internal void SetClasses(string[] cssClasses, int index = -1)
 		/// <param name="clipRect">The Clip rect to set, if any</param>
 		protected internal void ArrangeVisual(Rect rect, Rect? clipRect)
 		{
-			LayoutSlotWithMarginsAndAlignments =
-				VisualTreeHelper.GetParent(this) is UIElement parent && parent is not RootVisual
-					? rect.DeflateBy(parent.GetBorderThickness())
-					: rect;
+			LayoutSlotWithMarginsAndAlignments = rect;
 
 			if (FeatureConfiguration.UIElement.AssignDOMXamlProperties)
 			{