### Godot version

4.2 dev3

### System information

Windows 10.0.19045 - Vulkan (Forward+) - dedicated NVIDIA GeForce GTX 1060 (NVIDIA; 30.0.15.1403) - Intel(R) Core(TM) i7-7700HQ CPU @ 2.80GHz (8 Threads)

### Issue description

If you have a Method Track with multiple calls to the same method, they are joined together and makes things unreadable:
![image](https://github.com/godotengine/godot/assets/2223172/a2ab8446-28a1-440b-b0d5-5049f5d705b4)
The horizontal line shouldn't be used here. I think it might be a regression.

### Steps to reproduce

1. Add AnimationPlayer
2. Add a Method Track (with Add Track button)
3. Add some key to the track
4. Add another key with the same method

### Minimal reproduction project

N/A
box_selection->set_mouse_filter(MOUSE_FILTER_IGNORE);
	box_selection->hide();
	box_selection->connect("draw", callable_mp(this, &AnimationTrackEditor::_box_selection_draw));
	
	Ref<AnimationTrackEditDefaultPlugin> def_plugin;
	def_plugin.instantiate();
	add_track_edit_plugin(def_plugin);
	
	optimize_dialog = memnew(ConfirmationDialog);
	add_child(optimize_dialog);
	optimize_dialog->set_title(TTR("Animation Optimizer"));
	VBoxContainer *optimize_vb = memnew(VBoxContainer);
	optimize_dialog->add_child(optimize_vb);
	optimize_velocity_error = memnew(SpinBox);
	optimize_velocity_error->set_max(1.0);
	optimize_velocity_error->set_min(0.001);
	optimize_velocity_error->set_step(0.001);
	optimize_velocity_error->set_value(0.01);
	optimize_vb->add_margin_child(TTR("Max Velocity Error:"), optimize_velocity_error);
	optimize_angular_error = memnew(SpinBox);
	optimize_angular_error->set_max(1.0);
	optimize_angular_error->set_min(0.001);
	optimize_angular_error->set_step(0.001);
	optimize_angular_error->set_value(0.01);
	optimize_vb->add_margin_child(TTR("Max Angular Error:"), optimize_angular_error);
	optimize_precision_error = memnew(SpinBox);
	optimize_precision_error->set_max(6);
	optimize_precision_error->set_min(1);
	optimize_precision_error->set_step(1);
	optimize_precision_error->set_value(3);