Unpin mariadb:10.7 once 10.8 and 10.9 problems are solved

[stronk7]

We have just pinned MariaDB again, to 10.7, because just released 10.8 and 10.9 images have problems.

b93a840 and 88b8117

This issue is about to proceed to unpin it once the problems are gone.

[stronk7]

Interesting enough its seems to be some incompatibility with the new images (10.8 and 10.9) that use Ubuntu 22.04 (jammy) on older host OSs (we use 20.04).

10.7 is built using 20.04 (focal) and doesn't have that problem.

MariaDB/mariadb-docker#434

[stronk7]

Note that now that we have upgraded workers to 22.04 (jammy), MariaDB 10.8 and 10.9 are back to pass:

https://ci.moodle.org/view/Testing/job/DEV.01%20-%20Developer-requested%20Behat/28300

So, surely, we can proceed to unpin mariadb now (in few days, still have 1 worker to me upgraded).

Ciao :-)