Updating dotnet interactive to FSharp.Core and FSharp.Compiler.Service 8.0.400 causes test errors

[KevinRansom]

This PR in the dotnet interactive repo updates the F# packages to the latest RTM packages.

dotnet/interactive#3679

This causes tests issues for interactive:

[vzarytovskii]

Issue is caused by #16168

FYI @DedSec256

@KevinRansom @T-Gro can you please handle the revert/fix (whatever is easier). It will need to go to both 8 and 9 asap.

[T-Gro]

This reproes for FSI when used with the /usesdkrefs- flag.
Under it, the typedefiniton for "MemoryExtensions" signals that it does not contain extension methods (the regression added by #16168 ).

I will try a fix-forward rather than a revert here.

[T-Gro]

Fixed with #17799