Update test packages (#175)

* Update test packages

* downgrade voor .net6

---------

Co-authored-by: Julian Verdurmen <304NotModified@users.noreply.github.com>

Author: 304NotModified

tests/UTF-unknown.Tests.csproj

@@ -9,10 +9,10 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.2.0" />
-    <PackageReference Include="Newtonsoft.Json" Version="13.0.1" />
-    <PackageReference Include="NUnit" Version="3.13.3" />
-    <PackageReference Include="NUnit3TestAdapter" Version="4.2.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.13.0" />
+    <PackageReference Include="Newtonsoft.Json" Version="13.0.3" />
+    <PackageReference Include="NUnit" Version="3.14.0" />
+    <PackageReference Include="NUnit3TestAdapter" Version="4.6.0" />
   </ItemGroup>
 
   <ItemGroup>