Hong Kong is expecting about 30 new Covid-19 cases on Wednesday, as authorities continue to race to contain growing clusters in the city’s third wave of infections, including at an international container port.The figure from sources, if confirmed, will extend the city’s stretch of fewer than 100 daily cases to a 17th day. On Tuesday, the authorities confirmed 36 new cases, taking the overall count to 4,560 with 71 related deaths.But health officials have admitted difficulties in screening…