Onion service traffic v2 graph should be retired or archived

We are now showing two different graphs at https://metrics.torproject.org/hidserv-rend-relayed-cells.html one is onion service v3 traffic and the other one is v2. This is nowadays a flat, close to 0, line. I think we should either stop showing v2 traffic or make a new tab where we show v2 traffic separately.