Update xunit-dotnet monorepo

Author: renovate[bot]

Source/Cake.DotNetVersionDetector.Tests/Cake.DotNetVersionDetector.Tests.csproj

@@ -19,8 +19,8 @@
       <PrivateAssets>all</PrivateAssets>
     </PackageReference>
     <PackageReference Include="NSubstitute" Version="4.2.2" />
-    <PackageReference Include="xunit" Version="2.4.1" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3" />
+    <PackageReference Include="xunit" Version="2.9.0" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.8.2" />
   </ItemGroup>
 
   <ItemGroup>