RFE: Send automated notifications to "soon-next-in-line" maintainers

[rlemosor]

We noted that teams would appreciate being notified they were next in line (or soon to be) for maintaining a package whose dependency another team (so far the maintainer) had dropped. This would ideally be achieved via some automated means based on CR data.

For example: team A is the 3rd in the line of succession to maintain a package. Team Z is the current maintainer and has dropped the dependency. Accordingly, team A is now the 2nd in the line of succession for maintaining the package. Team Y is the likely new maintainer as soon as team Z negotiates it (which probably was already underway).

As such, a notification should be sent to team A alerting it of the new status quo, including the possibility of team Y also looking forward to dropping its dependency and thus request team A to own the package. Team A would then be advised to prepare for that possible state, which could encourage a possible elimination of the dependency as well.

[rlemosor]

Opened in minimization/content-resolver as minimization/content-resolver#37. Closing it here.