### Godot version

4.0.dev (c309de53997feff3286295fb2d71657f112a15db)

### System information

Linux, Nvidia, Vulkan

### Issue description

Editor segfaults when certain conditions are met when using the AnimationPlayer editor.

### Steps to reproduce

1. Create multiple animations, saved into a animation collection
2. Open an existing animation, then make a new empty animation
3. Change from seconds to fps, or add a new property to animate ()
4. Editor crashes

NOTE: It is slightly random and I have not found a perfect repro

### Minimal reproduction project

N/A (TBD?)
} else {
		hscroll->hide();
		edit->set_disabled(true);
		step->set_block_signals(true);
		step->set_value(0);
		step->set_block_signals(false);
		step->set_read_only(true);
		snap->set_disabled(true);
		snap_mode->set_disabled(true);
		bezier_edit_icon->set_disabled(true);
	}
}
void AnimationTrackEditor::_check_bezier_exist() {
	bool is_exist = false;
	for (int i = 0; i < animation->get_track_count(); i++) {
		if (animation->track_get_type(i) == Animation::TrackType::TYPE_BEZIER) {
			is_exist = true;
			break;
		}
	}
	if (is_exist) {
		bezier_edit_icon->set_disabled(false);
	} else {
		if (bezier_edit->is_visible()) {
			_cancel_bezier_edit();
		}
		bezier_edit_icon->set_disabled(true);
	}
}
Ref<Animation> AnimationTrackEditor::get_current_animation() const {