### 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
ERR_FAIL_INDEX(p_track, animation->get_track_count());
	ERR_FAIL_INDEX(p_key, animation->track_get_key_count(p_track));
	SelectedKey sk;
	sk.key = p_key;
	sk.track = p_track;
	selection.erase(sk);
	_redraw_tracks();
	_update_key_edit();
}
void AnimationTrackEditor::_move_selection_begin() {
	moving_selection = true;
	moving_selection_offset = 0;
}
void AnimationTrackEditor::_move_selection(float p_offset) {
	moving_selection_offset = p_offset;
	_redraw_tracks();
}
struct _AnimMoveRestore {
	int track = 0;
	float time = 0;
	Variant key;
	float transition = 0;
};
void AnimationTrackEditor::_clear_key_edit() {