feat: remove stale ONLINE_PRESENCE contact keys in redis (#9558)

50% of Redis memory size comes from ONLINE_PRESENCE keys. This PR adds a
periodic job to remove stale keys from all accounts.

app/services/internal/remove_stale_redis_keys_service.rb

@@ -0,0 +1,10 @@
+class Internal::RemoveStaleRedisKeysService
+  pattr_initialize [:account_id!]
+
+  def perform(account_id)
+    range_start = (Time.zone.now - PRESENCE_DURATION).to_i
+    # exclusive minimum score is specified by prefixing (
+    # we are clearing old records because this could clogg up the sorted set
+    ::Redis::Alfred.zremrangebyscore(presence_key(account_id, 'Contact'), '-inf', "(#{range_start}")
+  end
+end