Fix Release Notes WebView not being disposed (fix #3648)

Author: marticliment

src/UniGetUI/Pages/DialogPages/DialogHelper_Generic.cs

@@ -383,6 +383,7 @@ public static async void ShowReleaseNotes()
         notes.Close += (_, _) => NotesDialog.Hide();
         NotesDialog.Content = notes;
         await Window.ShowDialogAsync(NotesDialog);
+        notes.Dispose();
     }
 
     public static async void HandleBrokenWinGet()

src/UniGetUI/Pages/DialogPages/ReleaseNotes.xaml.cs

@@ -10,7 +10,7 @@ namespace UniGetUI.Interface.Dialogs
     /// <summary>
     /// An empty page that can be used on its own or navigated to within a Frame.
     /// </summary>
-    public sealed partial class ReleaseNotes : Page
+    public sealed partial class ReleaseNotes : Page, IDisposable
     {
 
         public event EventHandler<EventArgs>? Close;