add empty file to avoid fatals

changelog/revert-file-needed-for-plugin-update

@@ -0,0 +1,5 @@
+Significance: patch
+Type: dev
+Comment: This is the file revert to avoid failures on plugin update. This is a temporary solution. Both removal & revert happen on develop meaning there is no change to the outside world.
+
+

includes/admin/class-wc-rest-upe-flag-toggle-controller.php

@@ -0,0 +1,16 @@
+<?php
+/**
+ * Class WC_REST_UPE_Flag_Toggle_Controller
+ *
+ * @package WooCommerce\Payments\Admin
+ */
+
+defined( 'ABSPATH' ) || exit;
+
+use WCPay\Constants\Track_Events;
+
+/**
+ * REST controller for UPE feature flag. Needs to stay in the codebase to avoid error on plugin update for versions 6.9.2 or earlier.
+ */
+class WC_REST_UPE_Flag_Toggle_Controller extends WP_REST_Controller {
+}