### Godot version

v4.1.rc2.official [46424488e]

### System information

Godot v4.1.rc2 - Windows 10.0.22621 - Vulkan (Forward+) - dedicated NVIDIA GeForce RTX 3060 (NVIDIA; 31.0.15.3623) - AMD Ryzen 7 5700G with Radeon Graphics (16 Threads)

### Issue description

When setting the AnimationTree to active, Godot crashes.

### Steps to reproduce

https://github.com/godotengine/godot/assets/46705245/dbe5eb81-1357-43e8-ac80-a4eb97eea9fc

### Minimal reproduction project

[Crash.zip](https://github.com/godotengine/godot/files/11945826/Crash.zip)

for (int i = 0; i < p_state_machine->transitions.size(); i++) {
		if (p_state_machine->transitions[i].transition->get_advance_mode() == AnimationNodeStateMachineTransition::ADVANCE_MODE_DISABLED) {
			continue;
		}
		if (p_state_machine->transitions[i].from == current) {
			open_list.push_back(i);
			float cost = p_state_machine->states[p_state_machine->transitions[i].to].position.distance_to(current_pos);
			cost *= p_state_machine->transitions[i].transition->get_priority();
			AStarCost ap;
			ap.prev = current;
			ap.distance = cost;
			cost_map[p_state_machine->transitions[i].to] = ap;
			if (p_state_machine->transitions[i].to == travel) { 
				found_route = true;
				break;
			}
		}
	}
	
	while (!found_route) {
		if (open_list.size() == 0) {
			break; 
		}
		
		List<int>::Element *least_cost_transition = nullptr;
		float least_cost = 1e20;
		for (List<int>::Element *E = open_list.front(); E; E = E->next()) {
			float cost = cost_map[p_state_machine->transitions[E->get()].to].distance;
			cost += p_state_machine->states[p_state_machine->transitions[E->get()].to].position.distance_to(target_pos);
			if (cost < least_cost) {