chore(deps): update dependency microsoft.reactive.testing to 6.1.0 (#903)

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

Author: renovate[bot]

src/Directory.Packages.props

@@ -16,7 +16,7 @@
     <PackageVersion Include="coverlet.msbuild" Version="6.0.4" />
     <PackageVersion Include="DiffEngine" Version="16.2.3" />
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.14.1" />
-    <PackageVersion Include="Microsoft.Reactive.Testing" Version="6.0.2" />
+    <PackageVersion Include="Microsoft.Reactive.Testing" Version="6.1.0" />
     <PackageVersion Include="Microsoft.SourceLink.GitHub" Version="8.0.0" />
     <PackageVersion Include="Microsoft.Extensions.Logging.Debug" Version="9.0.8" />
     <PackageVersion Include="Nerdbank.GitVersioning" Version="3.8.118" />