Update the type to be explicitly nullable

Author: mudrd8mz

lib.php

@@ -103,7 +103,7 @@ public function supports_repositories() {
      * @param object $fpoptions file picker options
      * @return void
      */
-    public function use_editor($elementid, array $options=null, $fpoptions = null) {
+    public function use_editor($elementid, ?array $options = null, $fpoptions = null) {
         global $PAGE;
 
         $initparams = [