Removing internal reference

Author: niels9001

components/SettingsControls/src/SettingsExpander/SettingsExpander.cs

@@ -2,8 +2,6 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 // See the LICENSE file in the project root for more information.
 
-using CommunityToolkit.Labs.WinUI.Internal;
-
 namespace CommunityToolkit.Labs.WinUI;
 
 //// Note: ItemsRepeater will request all the available horizontal space: https://github.com/microsoft/microsoft-ui-xaml/issues/3842