It’s been more than 20 years, but “Desperate Housewives” star Dana Delany still won’t spill about her date with Sen. John Kerry - a night so strange it could have happened on Wisteria Lane! “Oh, it’s ancient history,” Dana demurred yesterday when we again tried to get her to give it up. “And it wasn’t really a bad date - it was just a good story.” The Phillips Andover alum met Kerry, then a bachelor, at a veterans event in D.C. when she was starring in the Vietnam-themed TV drama “China Beach.” The senator invited her to dinner then back...