Bump xunit from 2.8.0 to 2.9.0

Bumps xunit from 2.8.0 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

@@ -18,7 +18,7 @@
     <PackageVersion Include="Sendgrid" Version="9.29.3" />
     <PackageVersion Include="SharpZipLib" Version="1.4.2" />
     <PackageVersion Include="Testing.HttpClient" Version="1.0.0" />
-    <PackageVersion Include="xunit" Version="2.8.0" />
+    <PackageVersion Include="xunit" Version="2.9.0" />
     <PackageVersion Include="xunit.runner.visualstudio" Version="2.8.0" />
   </ItemGroup>
   <ItemGroup>