The only major airlines making money these days are busy flying cargo, not passengers. Of the world’s 30 largest airlines by revenue, just four reported profits for the April-June quarter, according to a Wall Street Journal analysis. They are all based in export-heavy South Korea or Taiwan, benefiting from the surge in demand for tech components and electronic gadgets as more people work from home, and for personal protective equipment, much of it produced in Asia. Continuing demand for automobile parts and other Asia-made…