Git commits in Moodle 3.8.9 by Huong Nguyen

commit f799c3042cbebab93d11d02d5075723110b2e8f5
Author: Huong Nguyen <huongn@moodle.com>
Date:   Thu, 22 Apr 2021 12:01:09 +0800
Tag:    v3.8.9

MDL-70720 Quiz: Improve capability checks when fetching users' best grades