fix(supported-version): override mysql to mysql:8.4 for Mage-OS 3.0.0 (#377)

Temporarily override the mysql build spec for Mage-OS 3.0.0 from
mariadb:11.4 to mysql:8.4 because mariadb does not work properly in the
release integration checks right now.

Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

Author: rhoerr