Auto-remove inactives from leaderboards

[JaggedAppliance]

As the title says. We have some campers on the top of the ladder leaderboards that need purging and some others who will play 1 game and go afk again if they aren't auto removed.

[Rackover]

Not related to the faf python server at all, I'm afraid.
Maybe ask in faf-java-api (they are the ones managing the leaderboards)