The Massachusetts Museum of Contemporary Art decided Tuesday to dismantle an uncompleted Christoph Büchel work without opening it to the public. A judge had ruled last week that MassMoCA could show the work, ignoring Büchel’s objections. “Buchel, who has rarely spoken to the press, sent an e-mail to the Globe Tuesday night in response to the museum’s move. Pointedly referencing his dispute with Mass MoCA over the project’s budget, he offered to donate a ‘permanent installation’ that wouldn’t cost anything to pull off. He concluded the email with an image of the plan — a tweak of the museum’s rooftop signage to spell out ‘Mass CoMA’.”