DB/Mana-Tombs: Migrate linked_respawn to spawn groups

src/server/scripts/Outland/Auchindoun/ManaTombs/instance_mana_tombs.cpp

@@ -31,6 +31,12 @@ class instance_mana_tombs : public InstanceMapScript
                 SetHeaders(DataHeader);
                 SetBossNumber(EncounterCount);
             }
+
+            void OnUnitDeath(Unit* unit) override
+            {
+                if (unit->GetEntry() == NPC_TAVAROK)
+                    SetBossState(DATA_TAVAROK, DONE);
+            }
         };
 
         InstanceScript* GetInstanceScript(InstanceMap* map) const override

src/server/scripts/Outland/Auchindoun/ManaTombs/mana_tombs.h

@@ -34,6 +34,11 @@ enum MTDataTypes
     DATA_YOR                    = 3
 };
 
+enum MTCreatureIds
+{
+    NPC_TAVAROK = 18343
+};
+
 template <class AI, class T>
 inline AI* GetManaTombsAI(T* obj)
 {