MIAMI — Jimmy Butler was back in attack mode. Luka Doncic was missing for the opposition. It was an advantage the Miami Heat needed. It was an advantage the Heat seized. With Butler scoring 33, including the tying basket at the end of regulation and a key basket in overtime, the Heat outlasted the Dallas Mavericks 123-118 in overtime Sunday night at Kaseya Center. “The efforts are starting to get a little bit more consistent,” coach Erik Spoelstra said. With the victory, the Heat moved back to .500, at 7-7, and ultimately had enough to offset 27 points from Dallas guard Kyrie Irving. “I feel like I’ve got to start attacking more often,” Butler said of his aggression.