Ensure shared framework consumes source-built RID graph

[ericstj]

Related to #50818

I believe the shared framework build process is still consuming the statically defined, checked-in, runtime.json.

We need to make sure it uses the generated one.

I suggest we do this by making the shared framework always consume it from an output location (along with the assemblies, etc). Then make the Microsoft.NETCore.Platforms project responsible for putting it there, whether it builds it or not.

Also we should consider scenarios like #52907 where folks want to add RIDs without necessarily doing a source build.

Perhaps there is a way to use the RID generation process in more conditions while still ensuring the checked-in copy is up-to-date?

I couldn't figure out the best area label to add to this issue. If you have write-permissions please help me learn by adding exactly one area label.

[ericstj]

Note that the fix here will likely require changes in installer and libraries. It's likely going to be me fixing this if I can find the time to get to it. Would love help identifying what to change in installer and how to test this sort of thing (EG: hypothetical new linux or new arch). cc @ViktorHofer @crummel

[ViktorHofer]

@NikolaMilosavljevic this seems important enough to keep in 6.0.

[ViktorHofer]

@ericstj as this issue still targets 6.0, do you have someone to work on it?

[ericstj]

I'll leave it to the owners of the area to make the call and fix it if they deem it necessary. I don't see it as must fix for 6.0 unless there's a source build scenario that requires it.