code_style: remove unused namespace using

Signed-off-by: leo <[email protected]>

Author: love-linger

src/ViewModels/LauncherPage.cs

@@ -2,7 +2,6 @@
 using System.Threading.Tasks;
 
 using Avalonia.Collections;
-using Avalonia.Media;
 
 using CommunityToolkit.Mvvm.ComponentModel;