Stop storing the parsed RID fallback graph (#82811)

Stop storing the parsed RID fallback graph (#82811)

After startup, we only need the RID fallback graph from the root framework for component dependency resolution (AssemblyDependencyResolver). This change stops storing that graph (which is decently large for portable linux) for all applications and switches to re-populating it on demand.

Removing this stored value also lines up with the plan to move to algorithmic RID selection rather than reading from the .deps.json.