Handle removal of free tagged releases for Bitnami's MariaDB Helm chart

We can no longer depend on free tagged releases for Drupal's MariaDB database:

Bitnami will begin deprecating support for non-hardened, Debian-based software images in its free tier and will gradually remove non-latest tags from the public catalog. As a result, community users will have access to a reduced number of hardened images. These images are published only under the “latest” tag and are intended for development purposes

See Upcoming changes to the Bitnami catalog (effective August 28th, 2025) #83267 for details.

Can we find another another Helm chart for the DB we can use instead?

Remaining tasks for the project

1. Find replacement
2. Implement it
3. Test on BackUpScale Staging environment
4. Merge MR
5. Tag release 2.0.0
6. Add release notes (see below)

Remaining tasks for BackUpScale

1. Tag master branch with updated submodule
2. Push it
3. Deploy to Prod
4. Delete old PVCs