[Perf] Make library AOT-compatible

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](https://github.com/CSBiology/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.