Infra changes required for stable builds

[Anipik]

• nowarn is required for a shipping package to depend on non-shipping package for core-setup
• adding back CopyNupkgAndChangeVersion.cs bcoz this is only used in stable versions
• making Microsoft.Extensions.HostFactoryResolver, System.Numerics.Tensors & Internal.Transport as non-shipping, non-stable

[ViktorHofer]

nowarn is required for a shipping package to depend on non-shipping package for core-setup

what is the non-shipping package here?

[ViktorHofer]

Usually we set the VersionSuffix in Versions.props. Why here only for libraries?

[Anipik]

VersionSuffix should be empty when stablizePackageVersion is set. We require this because of this library specific error check. https://github.com/dotnet/arcade/blob/master/src/Microsoft.DotNet.Build.Tasks.Packaging/src/build/Packaging.targets#L706
We have the same thing done in 3.1 as well. cc @ericstj
Not sure why this error check is here, we should probably resolve this for 6.0

[ericstj]

IIRC this was because of differences with how arcade decided to use VersionSuffix and the way it was already used by our packages. I believe we always want it it to be set and use the index to determine when something is stable vs not. Whereas Arcade decides if something should be stable based solely on properties, then only sets VersionSuffix for non-stable packages.

We could probably change our logic to allow for empty suffix, but then error if we ever tried to build a package that depended on some other package that wasn't represented stable in the index.

[ViktorHofer]

So should we follow-up on this?

[ericstj]

dotnet/arcade#6305

[ViktorHofer]

LGTM but please follow-up on the questions before merging.