fix(Scripts/BlackwingLair): Razorgore adds should spawn 45 seconds after Razorgore's combat engagement (#10641)

- Closes #10581

Co-authored-by: temperrr <temperrr@users.noreply.github.com>

src/server/scripts/EasternKingdoms/BlackrockMountain/BlackwingLair/boss_razorgore.cpp

@@ -89,6 +89,13 @@ public:
             return !(target->GetTypeId() == TYPEID_UNIT && !secondPhase);
         }
 
+        void EnterCombat(Unit* /*victim*/) override
+        {
+            _EnterCombat();
+
+            instance->SetData(DATA_EGG_EVENT, IN_PROGRESS);
+        }
+
         void DoChangePhase()
         {
             secondPhase = true;