Bump CommunityToolkit.Mvvm from 8.4.1 to 8.4.2

---
updated-dependencies:
- dependency-name: CommunityToolkit.Mvvm
  dependency-version: 8.4.2
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

src/Directory.Packages.props

@@ -14,7 +14,7 @@
     <PackageVersion Include="Avalonia.Headless.XUnit" Version="11.3.12" />
     <PackageVersion Include="Avalonia.Skia" Version="11.3.12" />
     <PackageVersion Include="Avalonia.Themes.Fluent" Version="11.3.12" />
-    <PackageVersion Include="CommunityToolkit.Mvvm" Version="8.4.1" />
+    <PackageVersion Include="CommunityToolkit.Mvvm" Version="8.4.2" />
     <PackageVersion Include="FluentAvaloniaUI" Version="2.5.0" />
     <PackageVersion Include="MarkdownSnippets.MsBuild" Version="28.0.1" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.3.0" />