chore(deps): update dependency tunit to 1.16.4 (#1517)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

src/Directory.Packages.props

@@ -28,7 +28,7 @@
     <PackageVersion Include="System.Net.Http" Version="4.3.4" />
     <PackageVersion Include="System.Reactive" Version="6.1.0" />
     <PackageVersion Include="System.Text.RegularExpressions" Version="4.3.1" />
-    <PackageVersion Include="TUnit" Version="1.15.11" />
+    <PackageVersion Include="TUnit" Version="1.16.4" />
     <PackageVersion Include="Verify.TUnit" Version="31.12.5" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
     <PackageVersion Include="Microsoft.Reactive.Testing" Version="6.1.0" />