chore(deps): update dependency microsoft.reactive.testing to 6.1.0 (#282)

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

Author: renovate[bot]

src/Directory.Packages.props

@@ -22,7 +22,7 @@
 	<!-- Test projects only -->
 	<ItemGroup>
     <PackageVersion Include="ReactiveUI.Testing" Version="21.0.1" />
-    <PackageVersion Include="Microsoft.Reactive.Testing" Version="6.0.2" />
+    <PackageVersion Include="Microsoft.Reactive.Testing" Version="6.1.0" />
 		<PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.14.1" />
 		<PackageVersion Include="NUnit" Version="4.4.0" />
 		<PackageVersion Include="NUnit3TestAdapter" Version="5.1.0" />