### 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
optimize_vb->add_margin_child(TTR("Max Precision Error:"), optimize_precision_error);
	optimize_dialog->set_ok_button_text(TTR("Optimize"));
	optimize_dialog->connect("confirmed", callable_mp(this, &AnimationTrackEditor::_edit_menu_pressed).bind(EDIT_OPTIMIZE_ANIMATION_CONFIRM));
	
	cleanup_dialog = memnew(ConfirmationDialog);
	add_child(cleanup_dialog);
	VBoxContainer *cleanup_vb = memnew(VBoxContainer);
	cleanup_dialog->add_child(cleanup_vb);
	cleanup_keys = memnew(CheckBox);
	cleanup_keys->set_text(TTR("Remove invalid keys"));
	cleanup_keys->set_pressed(true);
	cleanup_vb->add_child(cleanup_keys);
	cleanup_tracks = memnew(CheckBox);
	cleanup_tracks->set_text(TTR("Remove unresolved and empty tracks"));
	cleanup_tracks->set_pressed(true);
	cleanup_vb->add_child(cleanup_tracks);
	cleanup_all = memnew(CheckBox);
	cleanup_all->set_text(TTR("Clean-up all animations"));
	cleanup_vb->add_child(cleanup_all);
	cleanup_dialog->set_title(TTR("Clean-Up Animation(s) (NO UNDO!)"));
	cleanup_dialog->set_ok_button_text(TTR("Clean-Up"));
	cleanup_dialog->connect("confirmed", callable_mp(this, &AnimationTrackEditor::_edit_menu_pressed).bind(EDIT_CLEAN_UP_ANIMATION_CONFIRM));
	
	scale_dialog = memnew(ConfirmationDialog);
	VBoxContainer *vbc = memnew(VBoxContainer);
	scale_dialog->add_child(vbc);
	scale = memnew(SpinBox);
	scale->set_min(-99999);
	scale->set_max(99999);
	scale->set_step(0.001);