[Perf] Make library AOT-compatible

[alexandrehtrb]

Hello,

It would be interesting to make this library AOT-compatible, for performance benefits.

https://devblogs.microsoft.com/dotnet/creating-aot-compatible-libraries/

Also adding .NET 9 as a target framework.

I tested AOT compatibility on this repo and on FSharpAux repo, both seem to be OK.

In this repo, FSharp.Status seems to not use anymore OptimizedPriorityQueue package, maybe it could be removed from the fsproj.