Update todo.md to reflect CI/CD testing fix in GitHub Actions workflow

Author: jongalloway

doc/todo.md

@@ -47,6 +47,7 @@ The demo application is now fully functional with a modern .NET 9 Blazor Web App
 - ✅ **CI/CD Pipeline**: GitHub Actions workflow for automated builds, testing, code quality checks, security scanning, and NuGet package validation
 - ✅ **Core Data Models**: Complete implementation of NLWeb protocol request/response models with validation and JSON serialization
 - ✅ **Build Fixes**: Resolved App.razor build warnings by adding proper @using directives and removing duplicate files
+- ✅ **CI/CD Testing Fix**: Updated GitHub Actions workflow to gracefully handle missing test projects and prevent build failures
 
 The next phase focuses on implementing the core NLWeb library functionality.