During the last wave of security rebases of MariaDB 10.5 and MariaDB 10.11 in RHEL we forgot to include the new release of Galera, because of some confusion in the upstream release notes.

MariaDB 10.11.15 and 11.8.5 was released with new Galera 26.4.24.

WARNING:
Includes increasing the GCS protocol version, which prevents downgrades of individual nodes in the cluster as soon as all nodes have been updated.

We should add the new Galera release at the earliest convenience.