[Feature] - Support Modern .NET

[smaillet]

Convert code base to support a modern (LTS) version of .NET. .NET framework isn't something anyone should target anymore, and we are currently at .NET 9 with .NET 10 on the way soon. This
code base should abandon .NET Framework (and legacy C# versions that go with it) and move to a current version

Describe the solution you'd like
Convert code base to using at least .NET 8 (with an eye on support for .NET 10)

Describe alternatives you've considered
None really, leaving it in the land of unsupported frameworks means it goes EOL along with them.