chore(core): cleanup code p3 (#16073)

* Update MMapMgr.cpp

* Update UpdateFetcher.cpp

* Update AuctionHouseMgr.cpp

* Update AuctionHouseMgr.h

* Update BattlegroundAV.cpp

* Update ChannelMgr.cpp

* Update ThreatMgr.h

* Update Player.h

* Update PlayerSettings.cpp

* Update ObjectMgr.cpp

* Update Guild.cpp

* Update Guild.h

* Update Map.cpp

* Update World.cpp

* Update boss_nefarian.cpp

* Update boss_prince_malchezaar.cpp

* Update boss_venoxis.cpp

* Update zone_elwynn_forest.cpp

* Update zulfarrak.cpp

* Update boss_novos.cpp

src/server/game/Combat/ThreatMgr.h

@@ -259,7 +259,7 @@ public:
         if (threatList.empty())
             return;
 
-        for (auto ref : threatList)
+        for (auto& ref : threatList)
         {
             if (predicate(ref->getTarget()))
             {