Bump xunit from 2.6.3 to 2.6.6 (#219)

Bumps [xunit](https://github.com/xunit/xunit) from 2.6.3 to 2.6.6.
- [Commits](xunit/xunit@2.6.3...2.6.6)

---
updated-dependencies:
- dependency-name: xunit
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Directory.Packages.props

@@ -12,7 +12,7 @@
 
     <!-- Test deps -->
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.8.0"/>
-    <PackageVersion Include="xunit" Version="2.6.3"/>
+    <PackageVersion Include="xunit" Version="2.6.6"/>
     <PackageVersion Include="xunit.runner.visualstudio" Version="2.5.6"/>
     <PackageVersion Include="Unquote" Version="6.1.0"/>
   </ItemGroup>