Merge pull request #2094 from WordPress/use/wp-function-rest-endpoint

Use `wp_is_rest_endpoint()` to detect if we are handling a REST API request

Author: mukeshpanchal27

plugins/performance-lab/includes/server-timing/hooks.php

@@ -22,8 +22,7 @@
  * @return WP_REST_Response|WP_Error Filtered response.
  */
 function perflab_rest_post_dispatch_add_server_timing( $response ) {
-	// TODO: Change condition to use wp_is_rest_endpoint() once minimum-supported version is WordPress 6.5.
-	if ( ! defined( 'REST_REQUEST' ) || ! REST_REQUEST || ! $response instanceof WP_REST_Response ) {
+	if ( ! wp_is_rest_endpoint() || ! $response instanceof WP_REST_Response ) {
 		return $response;
 	}