New MySQL 8.0.21 & Percona XtraBackup 8.0.13 Complications

On Monday, July 13, 2020, Oracle released MySQL 8.0.21.  This release
contained a few new changes that cause complications with Percona XtraBackup.  See details at https://www.percona.com/blog/2020/07/21/new-mysql-8-0-21-and-percona-xtrabackup-8-0-13-issues/