.NET enable artifact layout

[LittleLittleCloud]

Why are these changes needed?

Enable artifact layout for .net project

• https://learn.microsoft.com/en-us/dotnet/core/sdk/artifacts-output

Related issue number

Checks

• [ ] I've included any doc changes needed for https://microsoft.github.io/autogen/. See https://microsoft.github.io/autogen/docs/Contribute#documentation to build and test documentation locally.
• [ ] I've added tests (if relevant) corresponding to the changes introduced in this PR.
• [ ] I've made sure all auto checks have passed.