Bump xunit from 2.8.1 to 2.9.0

Bumps xunit from 2.8.1 to 2.9.0.

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

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

Directory.Packages.props

@@ -31,7 +31,7 @@
  <!-- Test Package Versions -->
  <ItemGroup>
  <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.10.0" />
- <PackageVersion Include="xunit" Version="2.8.1" />
+ <PackageVersion Include="xunit" Version="2.9.0" />
  <PackageVersion Include="xunit.runner.visualstudio" Version="2.8.2" />
  <PackageVersion Include="FluentAssertions" Version="6.12.0" />
  <PackageVersion Include="coverlet.collector" Version="6.0.2" />