Removed unnecessary namespace reference and simplified OnOrientationChanged logic

Author: Avid29

components/Segmented/src/Segmented/Segmented.cs

@@ -160,11 +160,10 @@ private void OnOrientationChanged()
     {
         for (int i = 0; i < Items.Count; i++)
         {
-            var container = ContainerFromIndex(i) as SegmentedItem;
-            if (container is null)
-                continue;
-
-            container.UpdateOrientation(Orientation);
+            if (ContainerFromIndex(i) is SegmentedItem item)
+            {
+                item.UpdateOrientation(Orientation);
+            }
         }
     }
 }

components/Segmented/src/SegmentedItem/SegmentedItem.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 Windows.Media.Devices;
-
 namespace CommunityToolkit.WinUI.Controls;
 
 /// <summary>