WASHINGTON — As the U.S. economy rebounds from the COVID-19 pandemic, employers are turning to greater use of automation, including robots, rather than calling back workers or hiring new ones in many cases. The trend is affecting almost every sector, including manufacturing, distribution, transportation, retail, restaurants and many kinds of personal and government services. Airports have begun been using mobile robots to spray disinfecting chemicals on their facilities — work that janitors had initially done wearing moon suits and other personal protection equipment. The Pennsylvania Turnpike eliminated toll collection by hand and switched to a cashless electronic system. Advertisement Procter & Gamble, the maker of detergents, diapers, toilet paper and a cornucopia of other household goods, found that strategically adding robots to its assembly lines made it possible to keep more workers on the job — and produce more goods — while complying with social distancing guidelines.