Hi! Thanks for reporting. This is a regression from https://salsa.debian.org/mariadb-team/mariadb-server/-/commit/db57c0d8f20ebfe9f54f98941eabb1c774e696a3
The warning is just a warning and the installation/upgrade still completes, right? Seems upstream is aware of this issue and reworking this for next MariaDB minor releases in https://github.com/MariaDB/server/pull/3873
