The Late Night Wars, which began eight years ago when Jay Leno got the NBC “Tonight Show” job and David Letterman didn’t, is heating up again. Esquire magazine’s cover story for May reports makes much ado about the fact that Jay sent a get-well wish to Dave after his January quintuple heart bypass, only Dave reportedly has yet to acknowledge it. The article also suggests that Letterman’s “Late Show” executive producer Rob Burnett may have called Leno to try to stop him from wishing Dave well on the air — because Letterman is reportedly sick and tired of Leno’s good-guy image. Journalist Bill Zehme, who wrote the magazine story, told New York’s Daily News that since the article’s surfaced he’s heard from Leno, who said he’s tired of Letterman’s constant carping over not getting the “Tonight” spot. “Dave didn’t work to get the show,” Zehme quotes Leno as saying. “If you want to go to the prom, you have to show up for school.” Letterman had no comment.