Update policies as new Scalability team is introduced

Related to: scalability#1580

Before this is merged:

1. Update labels in Scalability tracker so that all the issues are for groupscalability instead of ~"team::Scalability"
2. Issues referenced in scalability#430 (closed) need to be changed to have the groupscalability instead of the ~"team::Scalability" label.
3. The code that generates scalability#430 (closed) must be changed to look for the groupscalability label.