REST API: Restore `wp-admin/includes/image.php` requirement in `WP_REST_Attachments_Controller::create_item()`.

Although the file is already included via the `::insert_attachment()` method, this addresses an inconsistency and corrects a misleading comment.

It also reduces the possibility of a future error in case `::insert_attachment()` is no longer called earlier in `::create_item()` at some point.

Follow-up to [43850] and [44206].

Props luisrivera.
Fixes #49449.
Built from https://develop.svn.wordpress.org/trunk@47296


git-svn-id: http://core.svn.wordpress.org/trunk@47096 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/rest-api/endpoints/class-wp-rest-attachments-controller.php

@@ -185,8 +185,9 @@ class WP_REST_Attachments_Controller extends WP_REST_Posts_Controller {
 			header( 'X-WP-Upload-Attachment-ID: ' . $attachment_id );
 		}
 
-		// Include media functions to get access to wp_generate_attachment_metadata().
+		// Include media and image functions to get access to wp_generate_attachment_metadata().
 		require_once ABSPATH . 'wp-admin/includes/media.php';
+		require_once ABSPATH . 'wp-admin/includes/image.php';
 
 		// Post-process the upload (create image sub-sizes, make PDF thumbnalis, etc.) and insert attachment meta.
 		// At this point the server may run out of resources and post-processing of uploaded images may fail.

wp-includes/version.php

@@ -13,7 +13,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '5.4-beta1-47295';
+$wp_version = '5.4-beta1-47296';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.