### 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
main_panel->add_child(timeline_scroll);
	timeline_scroll->set_v_size_flags(SIZE_EXPAND_FILL);
	VBoxContainer *timeline_vbox = memnew(VBoxContainer);
	timeline_scroll->add_child(timeline_vbox);
	timeline_vbox->set_v_size_flags(SIZE_EXPAND_FILL);
	timeline_vbox->set_h_size_flags(SIZE_EXPAND_FILL);
	timeline_vbox->add_theme_constant_override("separation", 0);
	info_message = memnew(Label);
	info_message->set_text(TTR("Select an AnimationPlayer node to create and edit animations."));
	info_message->set_vertical_alignment(VERTICAL_ALIGNMENT_CENTER);
	info_message->set_horizontal_alignment(HORIZONTAL_ALIGNMENT_CENTER);
	info_message->set_autowrap_mode(TextServer::AUTOWRAP_WORD_SMART);
	info_message->set_custom_minimum_size(Size2(100 * EDSCALE, 0));
	info_message->set_anchors_and_offsets_preset(PRESET_FULL_RECT, PRESET_MODE_KEEP_SIZE, 8 * EDSCALE);
	main_panel->add_child(info_message);
	timeline = memnew(AnimationTimelineEdit);
	timeline_vbox->add_child(timeline);
	timeline->connect("timeline_changed", callable_mp(this, &AnimationTrackEditor::_timeline_changed));
	timeline->connect("name_limit_changed", callable_mp(this, &AnimationTrackEditor::_name_limit_changed));
	timeline->connect("track_added", callable_mp(this, &AnimationTrackEditor::_add_track));
	timeline->connect("value_changed", callable_mp(this, &AnimationTrackEditor::_timeline_value_changed));
	timeline->connect("length_changed", callable_mp(this, &AnimationTrackEditor::_update_length));
	panner.instantiate();
	panner->set_callbacks(callable_mp(this, &AnimationTrackEditor::_pan_callback), callable_mp(this, &AnimationTrackEditor::_zoom_callback));
	scroll = memnew(ScrollContainer);
	timeline_vbox->add_child(scroll);
	scroll->set_v_size_flags(SIZE_EXPAND_FILL);
	VScrollBar *sb = scroll->get_v_scroll_bar();
	scroll->remove_child(sb);
	timeline_scroll->add_child(sb);