Support generation for dotnet 9.0

[doron050]

The project can't be updated to dotnet 9.0 due to wasm-wasi dotnet computability issue
dotnet/runtime#110111

find a workaround that allows users to generate dotnet 9.0 code without upgrading the whole solution

proposed solution
control the dotnet version through ci and run build under 8.0 and tests under 9.0