Fix build maybe?

Author: mohnjiles

StabilityMatrix.Avalonia/ViewModels/InstalledWorkflowsViewModel.cs

@@ -4,6 +4,7 @@
 using System.Text.Json;
 using System.Threading;
 using System.Threading.Tasks;
+using System.Reactive.Linq;
 using AsyncAwaitBestPractices;
 using Avalonia.Controls;
 using Avalonia.Platform.Storage;