For more than three decades, the Milwaukee Repertory Theater’s technically dazzling production of Charles Dickens’ classic tale A Christmas Carol has been one of Milwaukee’s most cherished Christmas traditions. This year’s production, which runs through Dec. 24 at the Pabst Theater, sees some major changes, with Christopher Donahue taking over from the great James Pickering as Scrooge, the reformed miser who learns to love Christmas after a long night of supernatural visits from his dead business partner and three ghosts. There have been some cuts and rearrangements to the script, but audiences will recognize the story well.