remove new woocommerce textual search by sku

functions.php

<?php
add_filter( 'request', function($query_vars) {
	global $wp_filter;
	foreach($wp_filter['request']->callbacks as $priority=>$callbacks) {
		foreach($callbacks as $unique_id=>$filter_array) {
			if ( is_array($filter_array['function']) && is_object( $filter_array['function'][0] ) && get_class( $filter_array['function'][0] ) && get_class( $filter_array['function'][0] ) == 'WC_Admin_List_Table_Products' && $filter_array['function'][1] == 'request_query' ) {
				unset( $wp_filter['request']->callbacks[ $priority ][ $unique_id ] );
			}
		}
	}
	return $query_vars;
},9,1);