Hamilton and The Phantom of the Opera, won’t reopen until next year, producers announced Wednesday, as arts bodies warned that Britain faces a “cultural catastrophe” because of the coronavirus pandemic.Producer Cameron Mackintosh, his producing partners and his Delfont Mackintosh Theatres group said Hamilton, The Phantom of the Opera, Mary Poppins and Les Miserables, would return “as early as practical in 2021.”The company said it was talking to staff about “potential redundancies.”Mackintosh,