Bump xunit.runner.visualstudio from 2.4.5 to 2.5.6 (#24)

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](https://github.com/xunit/visualstudio.xunit/compare/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>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

AtomicLibTests/AtomicLibTests.csproj

@@ -11,7 +11,7 @@
     <ItemGroup>
         <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.3.2" />
         <PackageReference Include="xunit" Version="2.4.2" />
-        <PackageReference Include="xunit.runner.visualstudio" Version="2.4.5">
+        <PackageReference Include="xunit.runner.visualstudio" Version="2.5.6">
             <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
             <PrivateAssets>all</PrivateAssets>
         </PackageReference>