Bump xunit from 2.6.5 to 2.6.6 (#1501)

Bumps [xunit](https://github.com/xunit/xunit) from 2.6.5 to 2.6.6.
- [Commits](https://github.com/xunit/xunit/compare/2.6.5...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>

tests/KubernetesClient.Tests/KubernetesClient.Tests.csproj

@@ -18,7 +18,7 @@
   <ItemGroup>
 
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.8.0" />
-    <PackageReference Include="xunit" Version="2.6.5" />
+    <PackageReference Include="xunit" Version="2.6.6" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.5.6">
       <PrivateAssets>all</PrivateAssets>
       <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>