### Godot version

4.0.rc

### System information

Any

### Issue description

If the RESET animation is generated at the same time as the Bezier track is generated, the bezier edit button will not be active.

![image](https://user-images.githubusercontent.com/61938263/218256176-88b1b196-7b6b-4404-84ad-e8694f23bb1b.png)

Also, if you delete a track in the Bezier Editor, or in undo redo, it will not update correctly.

### Steps to reproduce

![image](https://user-images.githubusercontent.com/61938263/218256230-4b0219d5-87e4-453a-8294-59f8feb0cfd5.png)


### Minimal reproduction project

N/A
float zv = zoom->get_max() - zoom->get_value();
	if (zv < 1) {
		zv = 1.0 - zv;
		return Math::pow(1.0f + zv, 8.0f) * 100;
	} else {
		return 1.0 / Math::pow(zv, 8.0f) * 100;
	}
}
void AnimationTimelineEdit::_anim_length_changed(double p_new_len) {
	if (editing) {
		return;
	}
	p_new_len = MAX(0.0001, p_new_len);
	if (use_fps && animation->get_step() > 0) {
		p_new_len *= animation->get_step();
	}
	editing = true;
	EditorUndoRedoManager *undo_redo = EditorUndoRedoManager::get_singleton();
	undo_redo->create_action(TTR("Change Animation Length"), UndoRedo::MERGE_ENDS);
	undo_redo->add_do_method(animation.ptr(), "set_length", p_new_len);
	undo_redo->add_undo_method(animation.ptr(), "set_length", animation->get_length());
	undo_redo->commit_action();
	editing = false;
	queue_redraw();
	emit_signal(SNAME("length_changed"), p_new_len);
}
void AnimationTimelineEdit::_anim_loop_pressed() {