BEIJING (Reuters) – The Beijing Winter Olympics will mainly rely on temporary and chartered flights from cities such as Tokyo and Singapore to bring in athletes for the Games due to China’s tight travel curbs and amid concerns over COVID-19, an official said on Friday. “The Omicron variant has already spread to over 50 countries, according to WHO data,” said Zhang Liang, an official with the Beijing Olympics organising committee, at a briefing. “The epidemic prevention situation is still severe and complicated.” The Beijing Olympics, which are due to begin on Feb. 4, will rely on chartered and…