BUG Mark $instance as internal to prevent being saved to config

src/Core/Config/ConfigLoader.php

@@ -10,6 +10,7 @@ use SilverStripe\Config\Collections\ConfigCollectionInterface;
 class ConfigLoader
 {
     /**
+     * @internal
      * @var self
      */
     private static $instance;

src/Core/Manifest/ClassLoader.php

@@ -13,6 +13,7 @@ class ClassLoader
 {
 
     /**
+     * @internal
      * @var ClassLoader
      */
     private static $instance;