chore(deps): update dependency microsoft.net.test.sdk to v17.9.0 (#21)

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

Author: renovate[bot]

src/directory.packages.props

@@ -30,7 +30,7 @@
     <PackageVersion Include="FluentAssertions" Version="6.10.0" />
     <PackageVersion Include="FluentAssertions.Analyzers" Version="0.16.0" />
     <PackageVersion Include="ReactiveUI.Testing" Version="18.4.26" />
-    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.5.0" />
+    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.9.0" />
     <PackageVersion Include="Microsoft.Reactive.Testing" Version="5.0.0" />
   </ItemGroup>