Fabulous nuget pacakge not listing an FSharp.Core dependency

[dsyme]

I notice the FSHarp.Core dependency is not being listed on the Fabulous nuget package, I'm not sure why, I guess it just needs an entry in the nuspec

https://www.nuget.org/packages/Fabulous/0.57.0

[dsyme]

Also components like Fabulous.XamarinForms.FFImageLoading are listing upward bound dependencies like (>= 0.55.0-preview3) for Fabulous and Fabulous.XamarinForms.

I think this should be more like 0.55.* or just = 0.55.0-preview3 since there's no guarantee of any binary API compat between Fabulous versions at the moment.

This came up in dotnet/fsharp#9370 which was using a mix of versions of components which were assuming binary compat

[TimLariviere]

Regarding FSharp.Core, I tried to follow the Notes and Guidance, but wasn't really sure what to do and ended up making it private.
I'll change that and pin it to 4.7.0 I guess? (it's the first targeting .NET Standard 2.0 directly)
https://github.com/fsprojects/Fabulous/blob/b75d01881c5c1c86d2989faf19dae9ce960422ba/Packages.targets#L23

For Fabulous.XamarinForms.FFImageLoading, it's a limitation of the new SDK-style projects.
NuGet automatically infers a >= constraint based on the project file when using a ProjectReference.
AFAIK there's no way to change that, except via writing an actual nuspec file.