Update xunit to v2

Author: renovate[bot]

Directory.Packages.props

@@ -39,9 +39,9 @@
     <PackageVersion Include="System.Threading.Tasks.Extensions" Version="4.6.0" />
     <PackageVersion Include="System.ValueTuple" Version="4.5.0" />
     <PackageVersion Include="xunit.abstractions" Version="2.0.3" />
-    <PackageVersion Include="Xunit.Combinatorial" Version="1.6.24" />
+    <PackageVersion Include="Xunit.Combinatorial" Version="2.0.24" />
     <PackageVersion Include="Xunit.SkippableFact" Version="1.5.23" />
-    <PackageVersion Include="Xunit.StaFact" Version="1.2.69" />
+    <PackageVersion Include="Xunit.StaFact" Version="2.0.44" />
   </ItemGroup>
   <ItemGroup Condition="'$(IsTestProject)'=='true'">
     <PackageVersion Update="Microsoft.CodeAnalysis" Version="$(CodeAnalysisVersionForTests)" />