ANTOINE ROLLAND SINCE the coronavirus forced his school to close in March, Papin has been working six days a week at a diamond mine in the Central African Republic (CAR) - hauling sacks of mud and rubble under a hot sun. He is among a dozen children working at the open-pit mine near the southern town of Ngoto, where about 100 miners use shovels and sieves to scour the red earth for diamonds. It is back-breaking work and Papin longs to return to the classroom. "I came here to help my big brother," Papin, who said he was 16 but…