### 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
if (!group_sort.has(base_path)) {
				AnimationTrackEditGroup *g = memnew(AnimationTrackEditGroup);
				Ref<Texture2D> icon = get_editor_theme_icon(SNAME("Node"));
				String name = base_path;
				String tooltip;
				if (root && root->has_node(base_path)) {
					Node *n = root->get_node(base_path);
					if (n) {
						icon = EditorNode::get_singleton()->get_object_icon(n, "Node");
						name = n->get_name();
						tooltip = root->get_path_to(n);
					}
				}
				g->set_type_and_name(icon, name, animation->track_get_path(i));
				g->set_root(root);
				g->set_tooltip_text(tooltip);
				g->set_timeline(timeline);
				groups.push_back(g);
				VBoxContainer *vb = memnew(VBoxContainer);
				vb->add_theme_constant_override("separation", 0);
				vb->add_child(g);
				track_vbox->add_child(vb);
				group_sort[base_path] = vb;
			}
			track_edit->set_in_group(true);
			group_sort[base_path]->add_child(track_edit);
		} else {
			track_edit->set_in_group(false);
			track_vbox->add_child(track_edit);
		}