MySQL 8.0: Prepare your old Drupal

Post en français ici. TL;DR: Older versions of Drupal does not work with MySQL 8.0. Update now. Brace yourself, MySQL 8.0 is coming soon on the databases delivered with your web hostings, also called "SharedSQL" (more info soon). After my post on old Wordpress, this one is about old Drupal. Issue Whether you installed it...