UI: Only show Amiibo bin scan menu item if the key file exists

src/Ryujinx/UI/Views/Main/MainMenuBarView.axaml

@@ -247,6 +247,7 @@
                     Click="OpenBinFile"
                     Header="{ext:Locale MenuBarActionsScanAmiiboBin}"
                     Icon="{ext:Icon mdi-cube-scan}"
+                    IsVisible="{Binding CanScanAmiiboBinaries}"
                     IsEnabled="{Binding IsAmiiboBinRequested}" />
                 <MenuItem
                     Command="{Binding TakeScreenshot}"

src/Ryujinx/UI/Views/Main/MainMenuBarView.axaml.cs

@@ -178,7 +178,7 @@ namespace Ryujinx.Ava.UI.Views.Main
         private void ScanBinAmiiboMenuItem_AttachedToVisualTree(object sender, VisualTreeAttachmentEventArgs e)
         {
             if (sender is MenuItem)
-                ViewModel.IsAmiiboBinRequested = ViewModel.IsAmiiboRequested && AmiiboBinReader.HasKeyRetailBinPath();
+                ViewModel.IsAmiiboBinRequested = ViewModel.IsAmiiboRequested && AmiiboBinReader.HasKeyRetailBinPath;
         }
 
         private async void InstallFileTypes_Click(object sender, RoutedEventArgs e)