Filters out a specific category from Storefront best sellers section on home page

storefront_best_seller_args.php

<?php // dont copy this line

add_filter( 'storefront_best_selling_products_shortcode_args', 'custom_storefront_best_selling_products');

function custom_storefront_best_selling_products( $args ) {
    $args['category'] = 'installation';
    $args['cat_operator'] = 'NOT IN';
    return $args;  
}