Bump xunit from 2.4.2 to 2.5.1

Bumps [xunit](https://github.com/xunit/xunit) from 2.4.2 to 2.5.1.
- [Commits](xunit/xunit@2.4.2...2.5.1)

---
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

@@ -8,7 +8,7 @@
     <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.6.2" />
     <PackageVersion Include="Validation" Version="2.5.51" />
     <PackageVersion Include="xunit.runner.visualstudio" Version="2.4.5" />
-    <PackageVersion Include="xunit" Version="2.4.2" />
+    <PackageVersion Include="xunit" Version="2.5.1" />
   </ItemGroup>
   <ItemGroup>
     <GlobalPackageReference Include="CSharpIsNullAnalyzer" Version="0.1.495" />