PHILADELPHIA — Brian Johnson is out as the Eagles’ offensive coordinator as Nick Sirianni goes about remaking his coaching staff, NFL sources told The Philadelphia Inquirer on Tuesday. Johnson’s firing doesn’t come as a shock considering the offensive regression in his first year as coordinator. The Eagles still had one of the better units in the NFL, but they dropped from third to eighth in total yards and third to seventh in points scored. The greater indictment of the offense came during an epic collapse that saw the 10-1 Eagles lose six of their last seven games, including a 32-9 loss to t…