core: Use single instance of profile manager

src/yuzu/multiplayer/lobby.h

@@ -24,10 +24,6 @@ namespace Core {
 class System;
 }
 
-namespace Service::Account {
-class ProfileManager;
-}
-
 /**
  * Listing of all public games pulled from services. The lobby should be simple enough for users to
  * find the game they want to play, and join it.
@@ -103,7 +99,6 @@ private:
 
     QFutureWatcher<AnnounceMultiplayerRoom::RoomList> room_list_watcher;
     std::weak_ptr<Core::AnnounceMultiplayerSession> announce_multiplayer_session;
-    std::unique_ptr<Service::Account::ProfileManager> profile_manager;
     QFutureWatcher<void>* watcher;
     Validation validation;
     Core::System& system;