Ensure 'enforce SSL connection' is set to enabled for Azure MariaDB Server

Enabling end-to-end TLS encryption can help keep data in-transit protected. In addition, using the latest version of TLS and modern ciphers can help keep data in-transit protected from man-in-the-middle and similar attacks.

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 Connection Security, set Enforce SSL connection to enabled.
4. Select Save

In Terraform -

1. In the azurerm_mariadb_server resource, set ssl_enforcement_enabled to true.

References:
https://learn.microsoft.com/en-us/azure/mariadb/howto-configure-ssl
https://registry.terraform.io/providers/hashicorp/azurerm/latest/docs/resources/mariadb_server#ssl_enforcement_enabled