Ensure regular backups are enabled for Azure MariaDB Server

Enabling automatic backups can help prevent data loss for a MariaDB server. Azure can create and save backups in either locally redundant or geo-redundant storage for greater resiliency. The maximum retention period for MariaDB backup storage is 35 days and they are encrypted by default. For more information, see the Azure documentation.
References:
https://learn.microsoft.com/en-us/azure/mariadb/concepts-backup

In Azure Console -

1. Open the Azure Portal and go to Azure Database for MariaDB servers.
2. Choose the MariaDB server you wish to edit.
3. Under Pricing tier, set Backup Retention Period to a value defined by the organization.
4. Set Locally Redundant - Recover from data loss within region as Backup redundancy option
5. Select Apply

In Terraform -

1. In the azurerm_mariadb_server resource, set backup_retention_days to a value defined by the organization.

References:
https://learn.microsoft.com/en-us/azure/mariadb/howto-restore-server-portal
https://registry.terraform.io/providers/hashicorp/azurerm/latest/docs/resources/mariadb_server#backup_retention_days