The legions of workers who built Dubai’s extravagant Expo 2020 site and keep it running face exploitation, grim conditions and a wide range of labour abuses, according to a new report released on Wednesday by a London-based labour rights group. The report by consultancy Equidem also said that the United Arab Emirates government had failed to demonstrate that its commitments to worker welfare at the multibillion-dollar Expo had corrected, let alone identified, rights violations. It comes after The Associated Press published an investigation based on interviews with over two dozen Expo workers a…