component/mariadb: use 10.4 (and drop 10.3)

We use to stick with 10.3 because of crashes with ERP5, but with 10.4.28
we don't have crashes anymore.

See https://jira.mariadb.org/browse/MDEV-23939 for the upstream bug and
!817 for a
reproduction in ERP5.
1 job for master
Status Job ID Name Coverage
  External
failed ERP5.UnitTest-Mariadb-10.4