Copy files from the sym-linked optimizer folder to the backup folder in the workspace.

def backup(self):
        """
        Copy files from the sym-linked optimizer folder to the backup folder in the workspace.
        """
        try:
            shutil.rmtree(self.backup_path)
        except FileNotFoundError:
            pass
        try:
            shutil.copytree(self.opt_path, self.backup_path)
        except shutil.Error as e:
            logger.exception(e)