chore(deps): update xunit-dotnet monorepo to v2.8.1

Author: renovate[bot]

src/directory.packages.props

@@ -25,8 +25,8 @@
   <ItemGroup>
     <PackageVersion Include="Tmds.ExecFunction" Version="0.7.1" />
     <PackageVersion Include="FluentAssertions" Version="6.12.0" />
-    <PackageVersion Include="xunit" Version="2.4.2" />
-    <PackageVersion Include="xunit.runner.visualstudio" Version="2.4.5" />
+    <PackageVersion Include="xunit" Version="2.8.1" />
+    <PackageVersion Include="xunit.runner.visualstudio" Version="2.8.1" />
     <PackageVersion Include="coverlet.collector" Version="6.0.2" />
   </ItemGroup>