Incompatible database backend version

I did not check the prerequisites for Zammad as the install is older than Sep 2023.
According to github this changed from 9.3+ to 10+ on 27/09/2023.

Tried to open the “mg-postgresql-10” issue on git but it gives a 404

Still any information about going from PostgreSQL 9.6 to 10 or higher is welcome. Seems just deleting the old version (so that version 13 is the only one) isn’t working.

Thanks a lot!

edit: referring to this post, I guess updating PostgreSQL 9.6 to 13 is out of the zammad scope, since it has nothing to do with Zammad. I believe we’re on an old version because we once did an inplace update from Debian 10 to 11. I’ll try to use some guides to migrate to 13.