### 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
pick_track->set_title(TTR("Pick a node to animate:"));
	pick_track->connect("selected", callable_mp(this, &AnimationTrackEditor::_new_track_node_selected));
	pick_track->get_filter_line_edit()->connect("text_changed", callable_mp(this, &AnimationTrackEditor::_pick_track_filter_text_changed));
	pick_track->get_filter_line_edit()->connect("gui_input", callable_mp(this, &AnimationTrackEditor::_pick_track_filter_input));
	prop_selector = memnew(PropertySelector);
	add_child(prop_selector);
	prop_selector->connect("selected", callable_mp(this, &AnimationTrackEditor::_new_track_property_selected));
	method_selector = memnew(PropertySelector);
	add_child(method_selector);
	method_selector->connect("selected", callable_mp(this, &AnimationTrackEditor::_add_method_key));
	insert_confirm = memnew(ConfirmationDialog);
	add_child(insert_confirm);
	insert_confirm->connect("confirmed", callable_mp(this, &AnimationTrackEditor::_confirm_insert_list));
	VBoxContainer *icvb = memnew(VBoxContainer);
	insert_confirm->add_child(icvb);
	insert_confirm_text = memnew(Label);
	icvb->add_child(insert_confirm_text);
	HBoxContainer *ichb = memnew(HBoxContainer);
	icvb->add_child(ichb);
	insert_confirm_bezier = memnew(CheckBox);
	insert_confirm_bezier->set_text(TTR("Use Bezier Curves"));
	insert_confirm_bezier->set_pressed(EDITOR_GET("editors/animation/default_create_bezier_tracks"));
	ichb->add_child(insert_confirm_bezier);
	insert_confirm_reset = memnew(CheckBox);
	insert_confirm_reset->set_text(TTR("Create RESET Track(s)", ""));
	insert_confirm_reset->set_pressed(EDITOR_GET("editors/animation/default_create_reset_tracks"));
	ichb->add_child(insert_confirm_reset);
	box_selection = memnew(Control);
	add_child(box_selection);
	box_selection->set_as_top_level(true);