Revert "Public roads: Dynamically set A* max search nodes"

This reverts commit acd67a0d0b.

src/road.cpp

@@ -947,6 +947,7 @@ static AyStar PublicRoadAyStar()
 	finder.GetNeighbours = PublicRoad_GetNeighbours;
 	finder.EndNodeCheck = PublicRoad_EndNodeCheck;
 	finder.FoundEndNode = PublicRoad_FoundEndNode;
+	finder.max_search_nodes = 1 << 20;
 	return finder;
 }
 
@@ -954,9 +955,6 @@ static bool PublicRoadFindPath(AyStar& finder, const TileIndex from, TileIndex t
 {
 	finder.user_target = reinterpret_cast<void *>(static_cast<uintptr_t>(to));
 
-	uint distance = DistanceManhattan(from, to);
-	finder.max_search_nodes = Clamp<uint32>(distance * distance * 64, 1 << 10, 1 << 20);
-
 	finder.Init(1 << _public_road_hash_size);
 
 	AyStarNode start {};