Update Microsoft.NET.Test.Sdk to get non-vulnerable versions of Newtonsoft.Json

Author: tautropfli

Directory.Packages.props

@@ -17,7 +17,7 @@
 		<PackageVersion Include="Microsoft.CodeAnalysis.PublicApiAnalyzers" Version="3.3.3" />
 	</ItemGroup>
 	<ItemGroup Label="Test Dependencies">
-		<PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.2.0" />
+		<PackageVersion Include="Microsoft.NET.Test.Sdk" Version="17.12.0" />
 		<PackageVersion Include="xunit" Version="2.9.3" />
 		<PackageVersion Include="xunit.runner.visualstudio" Version="3.0.1" />
 		<PackageVersion Include="FsCheck.Xunit" Version="2.16.4" />