Quiz override form class has moved

[matthewhilton]

Since Moodle 4.2 because of https://tracker.moodle.org/browse/MDL-74923 and https://tracker.moodle.org/browse/MDL-76614 the mod_quiz override form has moved to a namespaced class. So

moodle-local_assessfreq/classes/form/quiz_override_form.php

Line 30 in 1b9dd43

require_once($CFG->dirroot . '/mod/quiz/override_form.php');

is no longer valid.

It likely still works because of some class renaming magic https://github.com/moodle/moodle/blob/main/mod/quiz/db/renamedclasses.php#L56 but should be fixed (because this may be removed in later versions after full deprecation)