diff -r be944660c56a -r 3d72ae0968f4 wp/wp-includes/rest-api/endpoints/class-wp-rest-comments-controller.php
--- a/wp/wp-includes/rest-api/endpoints/class-wp-rest-comments-controller.php	Wed Sep 21 18:19:35 2022 +0200
+++ b/wp/wp-includes/rest-api/endpoints/class-wp-rest-comments-controller.php	Tue Sep 27 16:37:53 2022 +0200
@@ -1028,15 +1028,17 @@
 	 * Prepares a single comment output for response.
 	 *
 	 * @since 4.7.0
+	 * @since 5.9.0 Renamed `$comment` to `$item` to match parent class for PHP 8 named parameter support.
 	 *
-	 * @param WP_Comment      $comment Comment object.
+	 * @param WP_Comment      $item    Comment object.
 	 * @param WP_REST_Request $request Request object.
 	 * @return WP_REST_Response Response object.
 	 */
-	public function prepare_item_for_response( $comment, $request ) {
-
-		$fields = $this->get_fields_for_response( $request );
-		$data   = array();
+	public function prepare_item_for_response( $item, $request ) {
+		// Restores the more descriptive, specific name for use within this method.
+		$comment = $item;
+		$fields  = $this->get_fields_for_response( $request );
+		$data    = array();
 
 		if ( in_array( 'id', $fields, true ) ) {
 			$data['id'] = (int) $comment->comment_ID;
@@ -1194,7 +1196,8 @@
 			$rest_url = add_query_arg( $args, rest_url( $this->namespace . '/' . $this->rest_base ) );
 
 			$links['children'] = array(
-				'href' => $rest_url,
+				'href'       => $rest_url,
+				'embeddable' => true,
 			);
 		}