When exporting to "Brush Labels to coco", Ghost Keypoints used to prompt Sam2 have no 'x' and make an error

[mletombe]

So in label_studio_sdk/converter.py line 819, I did comment the keypoint treatment. I don't need them and it allowed me to go further but this is surely not the good way!

        """
        if keypoint_labels:
            kp_order = build_kp_order(self._schema)
            annotations.append(process_keypoints_for_coco(
                keypoint_labels,
                kp_order,
                annotation_id=len(annotations),
                image_id=image_id,
                category_name_to_id=category_name_to_id,
            ))
        """