add nunit adapter

Author: MatteoDelOmbra

Frends.Template/Frends.Echo.Execute/Frends.Echo.Execute.Tests/Frends.Echo.Execute.Tests.csproj

@@ -14,5 +14,6 @@
         <PackageReference Include="coverlet.collector" Version="6.*"/>
         <PackageReference Include="Microsoft.NET.Test.Sdk" Version="18.*" />
         <PackageReference Include="NUnit" Version="4.*"/>
+        <PackageReference Include="NUnit3TestAdapter" Version="6.*" />
     </ItemGroup>
 </Project>