remove pps from heartbeat

"PPS has no meaning anymore and is completely irrelevant. You should
ignore it, it is not an indicator of ANYTHING. If it’s high, that means
NOTHING. If it’s low, that means NOTHING. If it’s -, that means
NOTHING."

It's packets per second per player per vehicle, but is only sent every
30 seconds, its not averaged, and on the client-side, it shows a ping
icon next to it.

A client can open a new connection to the server and send a `P`, and
measure the time to the `P` response packet. The connection is then
closed. This was added ages ago, please use this instead for ping :)

src/THeartbeatThread.cpp

@@ -40,8 +40,6 @@ void THeartbeatThread::operator()() {
             Body += "&ip=" + Application::Settings.CustomIP;
         }
 
-        Body += "&pps=" + Application::PPS();
-
         auto SentryReportError = [&](const std::string& transaction, int status) {
             auto Lock = Sentry.CreateExclusiveContext();
             Sentry.SetContext("heartbeat",