function shouldIgnoreZone(node) {
    return !!node.closest(`[${SHADOW_ELEMENT_HINT_ATTRIBUTE_NAME}="true"]`);
}
If the user marked something in the ancestry of our node as shadow element, we can ignore it
We need the user to mark it for us because svelte updates the action from deep to shallow (but renders top down)
@param {HTMLElement} node
@return {boolean}