Public service concession contract. Action to set aside an arbitration award. Arbitral tribunal that held itself competent to decide on the validity of sanctions and administrative acts. Objective arbitrability (subject-matter arbitrability) limited to the economic effects of the penalties (article 151, sole paragraph, of Law 14,133/21). Jurisdiction of the arbitration tribunal set aside as to the merits of the imposition of the penalties, preserved only as to their financial consequences: