By Prakash MATHEMA / AFP Summiting the world’s 8,000-metre mountains is the ultimate bucket list dream for ambitious climbers, a feat managed by fewer than 50 people, and Sanu Sherpa is the first to do it twice. Summiting the world’s 8,000-metre mountains is the ultimate bucket list dream for ambitious climbers, a feat managed by fewer than 50 people, and Sanu Sherpa is the first to do it twice. The Nepali climber’s summit of Pakistan’s Gasherbrum II (8,035 metres, 26,362 feet) last month completed his unprecedented double ascent of the eight-thousanders — as the 14 peaks are collectively kno…