Add missing questionnaire.class.php require_once in lib.php callbacks

questionnaire_delete_instance() and questionnaire_reset_userdata() call
\questionnaire::delete_survey() and \questionnaire::get_survey_list()
(Phase 6d migrations) but were missing the require_once for the class file.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

Author: mchurchward

lib.php

@@ -219,6 +219,7 @@ function questionnaire_update_instance($questionnaire) {
 function questionnaire_delete_instance($id) {
     global $DB, $CFG;
     require_once($CFG->dirroot . '/mod/questionnaire/locallib.php');
+    require_once($CFG->dirroot . '/mod/questionnaire/questionnaire.class.php');
 
     if (! $questionnaire = $DB->get_record('questionnaire', ['id' => $id])) {
         return false;
@@ -1395,6 +1396,7 @@ function questionnaire_reset_userdata($data) {
     global $CFG, $DB;
     require_once($CFG->libdir . '/questionlib.php');
     require_once($CFG->dirroot . '/mod/questionnaire/locallib.php');
+    require_once($CFG->dirroot . '/mod/questionnaire/questionnaire.class.php');
 
     $componentstr = get_string('modulenameplural', 'questionnaire');
     $status = [];