Build errors when compliling with the .NET 9 SDK

[Numpsy]

I just tried building the solution with the 9.0.200 .NET SDK (the default/latest on this machine) and got a few build errors about attribute usage. e.g

I think this is hitting the issue discussed at dotnet/fsharp#18298 (comment) where the compiler is enforcing the attributes more than it used to and it needs a newer FSharp.Core to work.

Pinning the build to a .NET 8 SDK with global.json avoids the issue, but otherwise it might need either an FSharp.Core update or attribute changes to fix properly?

[JaggerJo]

We should probably bump the version of FSharp.Core then 👍