LONDON — William Frostman, a lighting supervisor who has toured with the Rolling Stones and Queen, has just spent a whole year at home, the longest time in his decades-long career. “I just want to wake up on a bus,” Frostman, 60, told dozens of his fellow roadies...Nostalgic as he was for life on the road, there were a few fears at the back of his mind, he said: Would anyone employ him? How would a vaccine passport work? ...But for many roadies — who often rely on monthslong world tours to make a living — a return to full-time...