[debian-mysql] Bug#990708: Bug#990708: Bug#990708: mariadb-server-10.5: upgrade problems due to galera-3 -> galera-4 switch

[Otto Kekäläinen]

> I do have this in a VM so I think we can easily repro this.
>
> // Fresh VM install from debian-10.9.0-i386-netinst.iso
> # history
>     1  visudo
>     2  rm /etc/motd
>     3  poweroff
>     4  apt install mariadb-server
>     5  dpkg -l|grep mariadb
>     6  sed -i 's/buster/bullseye/g' /etc/apt/sources.list
>     7  apt update
>     8  apt upgrade
>     9  apt dist-upgrade // output below
>    10  dpkg -l|grep mariadb // output below
>    11  apt dist-upgrade // output below

I added a CI job that runs about these and indeed it ends up removing
mariadb-server, and thus the upgrade does not progress.

https://salsa.debian.org/mariadb-team/mariadb-10.5/-/commit/3c93860e3c065c44e007405915fa762468c82afa
https://salsa.debian.org/mariadb-team/mariadb-10.5/-/jobs/1743608

Now this is reproducible, good.