chore(deps): update dependency nunit3testadapter to v6 (#108)

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

Author: renovate[bot]

src/Directory.Packages.props

@@ -24,7 +24,7 @@
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="18.0.1" />
     <PackageVersion Include="Microsoft.Reactive.Testing" Version="6.1.0" />
     <PackageVersion Include="NUnit" Version="4.4.0" />
-    <PackageVersion Include="NUnit3TestAdapter" Version="5.2.0" />
+    <PackageVersion Include="NUnit3TestAdapter" Version="6.0.0" />
     <PackageVersion Include="NUnit.Analyzers" Version="4.11.2" />
     <PackageVersion Include="DynamicData" Version="9.4.1" />
   </ItemGroup>