### 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
bake_fps->set_max(999);
	bake_fps->set_step(1);
	bake_fps->set_value(30); 
	bake_grid->add_child(memnew(Label(TTR("3D Pos/Rot/Scl Track:"))));
	bake_grid->add_child(bake_trs);
	bake_grid->add_child(memnew(Label(TTR("Blendshape Track:"))));
	bake_grid->add_child(bake_blendshape);
	bake_grid->add_child(memnew(Label(TTR("Value Track:"))));
	bake_grid->add_child(bake_value);
	bake_grid->add_child(memnew(Label(TTR("FPS:"))));
	bake_grid->add_child(bake_fps);
	
	track_copy_dialog = memnew(ConfirmationDialog);
	add_child(track_copy_dialog);
	track_copy_dialog->set_title(TTR("Select Tracks to Copy"));
	track_copy_dialog->set_ok_button_text(TTR("Copy"));
	VBoxContainer *track_copy_vbox = memnew(VBoxContainer);
	track_copy_dialog->add_child(track_copy_vbox);
	Button *select_all_button = memnew(Button);
	select_all_button->set_text(TTR("Select All/None"));
	select_all_button->connect("pressed", callable_mp(this, &AnimationTrackEditor::_select_all_tracks_for_copy));
	track_copy_vbox->add_child(select_all_button);
	track_copy_select = memnew(Tree);
	track_copy_select->set_h_size_flags(SIZE_EXPAND_FILL);
	track_copy_select->set_v_size_flags(SIZE_EXPAND_FILL);
	track_copy_select->set_hide_root(true);
	track_copy_vbox->add_child(track_copy_select);
	track_copy_dialog->connect("confirmed", callable_mp(this, &AnimationTrackEditor::_edit_menu_pressed).bind(EDIT_COPY_TRACKS_CONFIRM));
}
AnimationTrackEditor::~AnimationTrackEditor() {