Bump xunit.runner.visualstudio from 2.4.5 to 2.5.6

Bumps [xunit.runner.visualstudio](https://github.com/xunit/visualstudio.xunit) from 2.4.5 to 2.5.6.
- [Release notes](https://github.com/xunit/visualstudio.xunit/releases)
- [Commits](xunit/visualstudio.xunit@v2.4.5...2.5.6)

---
updated-dependencies:
- dependency-name: xunit.runner.visualstudio
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Directory.Packages.props

@@ -21,7 +21,7 @@
     <PackageVersion Include="MSBuild.ProjectCreation" Version="10.0.0" />
     <PackageVersion Include="Shouldly" Version="4.2.1" />
     <PackageVersion Include="xunit" Version="2.6.0" />
-    <PackageVersion Include="xunit.runner.visualstudio" Version="2.4.5" />
+    <PackageVersion Include="xunit.runner.visualstudio" Version="2.5.6" />
   </ItemGroup>
   <ItemGroup>
     <GlobalPackageReference Include="Microsoft.Build.Artifacts" Version="6.0.6" Condition="'$(EnableArtifacts)' != 'false'" />