Bump the xuint group with 2 updates (#571)

Bumps the xuint group with 2 updates: [xunit](https://github.com/xunit/xunit) and [xunit.runner.visualstudio](https://github.com/xunit/visualstudio.xunit).


Updates `xunit` from 2.6.1 to 2.6.2
- [Commits](xunit/xunit@2.6.1...2.6.2)

Updates `xunit.runner.visualstudio` from 2.5.3 to 2.5.4
- [Release notes](https://github.com/xunit/visualstudio.xunit/releases)
- [Commits](xunit/visualstudio.xunit@2.5.3...2.5.4)

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

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

tests/Directory.Build.props

@@ -14,8 +14,8 @@
   <ItemGroup>
     <PackageReference Include="MartinCostello.Logging.XUnit" Version="0.3.0" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
-    <PackageReference Include="xunit" Version="2.6.1" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.5.3" />
+    <PackageReference Include="xunit" Version="2.6.2" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.5.4" />
     <PackageReference Include="coverlet.collector" Version="6.0.0" />
   </ItemGroup>