Repo upgrade

[plabadaris]

Hello,
Since the https://github.com/microsoft/chat-copilot repo is upgraded to SK V1.4, this repo also needs upgrade (the sk-csharp-chatgpt-plugin project can be tested with chat-copilot).
All the starter projects are outdated, they're left back in .NET 6 and have references to preview version packages.
Are there any future updates or roadmap items that you are considering at the moment?
Thanks

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