Git commits in Moodle 3.9.7 by Michael Hawkins

commit a8c569c3688f8f2afc7a53918a54372545386ef3
Author: Michael Hawkins <michaelh@moodle.com>
Date:   Tue, 06 Apr 2021 13:01:19 +0800
Tag:    v3.9.7

MDL-70595 core: Updated security.txt expiry