fix: Don't fail on disposed color changes

src/Uno.UI/UI/Xaml/Controls/TextBox/TextBoxView.Android.cs

@@ -28,6 +28,7 @@ internal partial class TextBoxView : EditText, DependencyObject
 		internal TextBox? Owner => _ownerRef?.Target as TextBox;
 
 		private Action? _foregroundChanged;
+		private bool _isDisposed;
 
 		public TextBoxView(TextBox owner)
 			: base(ContextHelper.Current)
@@ -313,10 +314,23 @@ private void OnForegroundChanged(Brush oldValue, Brush newValue)
 
 				void ApplyColor()
 				{
+					if (_isDisposed)
+					{
+						// Binding changes may happen after the
+						// underlying control has been disposed
+						return;
+					}
+
 					SetTextColor(scb.Color);
 					SetCursorColor(scb.Color);
 				}
 			}
 		}
+
+		protected override void Dispose(bool disposing)
+		{
+			_isDisposed = true;
+			base.Dispose(disposing);
+		}
 	}
 }