refs and cleanup

Author: SimonCropp

src/Directory.Packages.props

@@ -14,7 +14,7 @@
     <PackageVersion Include="Microsoft.EntityFrameworkCore.Relational" Version="9.0.1" />
     <PackageVersion Include="Microsoft.EntityFrameworkCore.Sqlite" Version="9.0.1" />
     <PackageVersion Include="Microsoft.EntityFrameworkCore.SqlServer" Version="9.0.1" />
-    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
+    <PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.13.0" />
     <PackageVersion Include="NUnit" Version="4.3.2" />
     <PackageVersion Include="NUnit3TestAdapter" Version="4.6.0" />
     <PackageVersion Include="Polyfill" Version="7.5.0" />