CLEVELAND — Donovan Mitchell gave a blast of life to the home fans inside Rocket Mortgage FieldHouse, with a three-pointer that sliced what had been a 10-point deficit to one with 14 seconds to play. And when Tyrese Maxey missed his first of two free throws about seven seconds later, hope still permeated. But then Paul Reed blocked Mitchell inside, and Darius Garland misfired on an open three-pointer from the corner off the loose ball. The shorthanded 76ers held on for a 123-121 victory Monday night against the red-hot Cavaliers, capturing perhaps their most impressive win of the season so far…