BUDAPEST — Hungarian President Tamás Sulyok, an appointee of former Prime Minister Viktor Orbán, on Friday approved a constitutional amendment barring the same Orbán from returning to office. The amendment limits prime ministers to no more than eight years in office. Orbán served a total of 20 years. The Hungarian parliament overwhelmingly approved the amendment on Monday, sending it to the president’s desk for his signature. The amendment follows a longtime campaign promise by the Magyar