Function clearLeavingNodes

packages/core/src/animation/utils.ts:152–161

(tNode: TNode, el: HTMLElement)

 * This actually removes the leaving HTML Element in the TNode
 */
export function clearLeavingNodes(tNode: TNode, el: HTMLElement): void {
  const nodes = leavingNodes.get(tNode);
  if (nodes && nodes.length > 0) {
    const ix = nodes.findIndex((node) => node.el === el);
    if (ix > -1) nodes.splice(ix, 1);
  }
  if (nodes?.length === 0) {
    leavingNodes.delete(tNode);
  }
}

/**
 * In the case that we have an existing node that's animating away in a