Core/Creatures: Exclude despawned creatures from being found by "nearest entry" searchers

Updates #11418
Closes #17706

src/server/game/Grids/Notifiers/GridNotifiers.h

@@ -1169,7 +1169,7 @@ namespace Trinity
 
             bool operator()(Creature* u)
             {
-                if (u->GetEntry() == i_entry && u->IsAlive() == i_alive && i_obj.IsWithinDistInMap(u, i_range))
+                if (u->getDeathState() != DEAD && u->GetEntry() == i_entry && u->IsAlive() == i_alive && i_obj.IsWithinDistInMap(u, i_range))
                 {
                     i_range = i_obj.GetDistance(u);         // use found unit range as new range limit for next check
                     return true;