Who needs soft-on-crime judges when the district attorney doesn’t even want to lock up the bad guys?Manhattan’s new DA has ordered his prosecutors to stop seeking prison sentences for hordes of criminals and to downgrade felony charges in cases including armed robberies and drug dealing, according to a set of progressive policies made public Tuesday.In his first memo to staff on Monday, Alvin Bragg said his office “will not seek a carceral sentence” except with homicides and a handful of other cases, including domestic violence felonies, some sex crimes and public corruption.