### 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 (key_edit) {
		
		if (InspectorDock::get_inspector_singleton()->get_edited_object() == key_edit) {
			EditorNode::get_singleton()->push_item(nullptr);
		}
		
		memdelete(key_edit);
		key_edit = nullptr;
	}
	if (multi_key_edit) {
		if (InspectorDock::get_inspector_singleton()->get_edited_object() == multi_key_edit) {
			EditorNode::get_singleton()->push_item(nullptr);
		}
		memdelete(multi_key_edit);
		multi_key_edit = nullptr;
	}
}
void AnimationTrackEditor::_clear_selection(bool p_update) {
	selection.clear();
	if (p_update) {
		_redraw_tracks();
	}
	_clear_key_edit();
}
void AnimationTrackEditor::_update_key_edit() {