Ensure border stroke does not regenerate on Parent or Window property…

… changes (#24125)

Co-authored-by: Mike Corsaro <mikecorsaro@microsoft.com>

src/Controls/src/Core/Border/Border.cs

@@ -65,7 +65,14 @@ void NotifyStrokeShapeChanges()
  if (strokeShape is VisualElement visualElement)
  {
  AddLogicalChild(visualElement);
- _strokeShapeChanged ??= (sender, e) => OnPropertyChanged(nameof(StrokeShape));
+ _strokeShapeChanged ??= (sender, e) =>
+ {
+ if (e.PropertyName != nameof(Window) &&
+ e.PropertyName != nameof(Parent))
+ {
+ OnPropertyChanged(nameof(StrokeShape));
+ }
+ };
  _strokeShapeProxy ??= new();
  _strokeShapeProxy.Subscribe(visualElement, _strokeShapeChanged);
  }