It was supposed to be a “patriotic puppy parade,” kicking off the Memorial Day weekend with a festive gathering of dog owners and their pets. Now the Sussex County event is evolving into a somber gathering, a vigil for the 21 people who were fatally shot — 19 children and two teachers — at a Texas elementary school on Tuesday. The Vigil for Uvalde is being organized by the Sussex County Democratic Committee. It is scheduled to be held on the Newton Green at 12:30 p.m. Saturday instead of the more lighthearted puppy parade that was previously planned. “In light of what happened, we decided to p…