jQuery@1.12.4 was not removed

I figured out I can just put the code below into the functions.php file in my theme.

function load_custom_scripts() {
    wp_deregister_script( 'jquery' );
    wp_register_script('jquery', '//code.jquery.com/jquery-3.4.1.min.js', array(), '3.4.1', true); // true will place script in the footer
    wp_enqueue_script( 'jquery' );
}
if(!is_admin()) {
    add_action('wp_enqueue_scripts', 'load_custom_scripts', 99);
}