Change the number of columns in which products will be shown on product archives

wc-shop-loop-columns.php

<?php

add_filter( 'loop_shop_columns', 'wc_loop_shop_columns', 1, 10 );

/*
 * Return a new number of maximum columns for shop archives
 * @param int Original value
 * @return int New number of columns
 */
function wc_loop_shop_columns( $number_columns ) {
	return 2;
}