Add same class to author link and category.php

<?php 

function add_my_custom_class( $attributes ) {
    if ( is_single() ) {
          $attributes['class'] = $attributes['class'] . ' line-link';
      }
    return $attributes;
}
 
add_filter( 'genesis_attr_entry-categories', 'add_my_custom_class' );
add_filter( 'genesis_attr_entry-author-link', 'add_my_custom_class' );