Update xunit-dotnet monorepo

Author: renovate[bot]

Diff for: Tests/Directory.Build.props

@@ -9,8 +9,8 @@
     <PackageReference Include="JunitXml.TestLogger" Version="3.0.134" />
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.7.2" />
     <PackageReference Include="Moq" Version="4.20.69" />
-    <PackageReference Include="xunit" Version="2.5.1" />
-    <PackageReference Include="xunit.runner.visualstudio" PrivateAssets="All" Version="2.5.1">
+    <PackageReference Include="xunit" Version="2.6.5" />
+    <PackageReference Include="xunit.runner.visualstudio" PrivateAssets="All" Version="2.5.6">
       <IncludeAssets>runtime; build; native; contentfiles; analyzers</IncludeAssets>
     </PackageReference>
   </ItemGroup>