fix(Core/Entities): mobs called for help should check if can see and detect the enemy (#7493)

- Updates #7125

src/server/game/Entities/Creature/Creature.cpp

@@ -2233,6 +2233,12 @@ bool Creature::CanAssistTo(const Unit* u, const Unit* enemy, bool checkfaction /
     if (!IsHostileTo(enemy))
         return false;
 
+    // Check if can see the enemy
+    if (!CanSeeOrDetect(enemy))
+    {
+        return false;
+    }
+
     return true;
 }