BYOC sample with .NET Interactive

Hello,

Compared to iCsharp, .NET Interactive is more popular and well-maintained [fully supported Jupyter kernel](https://github.com/dotnet/interactive/blob/main/docs/NotebookswithJupyter.md). The BYOC C# sample could benefit from .NET Interactive and it would open the [support of additional languages](https://github.com/dotnet/interactive?tab=readme-ov-file#what-is-net-interactive) automatically.

Start by locating the BYOC C# sample and checking how it currently uses iCsharp. Compare that setup with the linked .NET Interactive Jupyter documentation, then verify that the sample runs with .NET Interactive and supports the intended additional languages.

Written by the indexing model from the issue text.