Always invalidate the visual explicitly when the TextLayout is invalidated (#16481)

Co-authored-by: Julien Lebosquain <julien@lebosquain.net>
Co-authored-by: Max Katz <maxkatz6@outlook.com>

src/Avalonia.Controls/Presenters/TextPresenter.cs

@@ -604,6 +604,7 @@ namespace Avalonia.Controls.Presenters
             _textLayout?.Dispose();
             _textLayout = null;
 
+            InvalidateVisual();
             InvalidateMeasure();
         }
 

src/Avalonia.Controls/TextBlock.cs

@@ -684,6 +684,7 @@ namespace Avalonia.Controls
         /// </summary>
         protected void InvalidateTextLayout()
         {
+            InvalidateVisual();
             InvalidateMeasure();
         }