Update dependency xunit.runner.visualstudio to v3

Author: renovate[bot]

tests/tests.csproj

@@ -9,7 +9,7 @@
   <ItemGroup>
     <PackageReference Include="Microsoft.NET.Test.Sdk" Version="15.7.0" />
     <PackageReference Include="xunit" Version="2.3.1" />
-    <PackageReference Include="xunit.runner.visualstudio" Version="2.3.1" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="3.1.1" />
     <DotNetCliToolReference Include="dotnet-xunit" Version="2.3.1" />
   </ItemGroup>