Ironic-image allows unauthenticated local access to Ironic API

Summary

Ironic-image is an OpenStack Ironic deployment packaged and configured by Metal3. When the reverse proxy mode is enabled by the `IRONIC_REVERSE_PROXY_SETUP` variable set to `true`, 1) HTTP basic credentials are validated on the HTTPD side in a separate container, not in the Ironic service itself and 2) Ironic listens in host network on a private port 6388 on localhost by default. As a result, when the reverse proxy mode is used, any Pod or local Unix user on the control plane Node can access the Ironic API on the private port without authentication. A similar problem affects Ironic Inspector (`INSPECTOR_REVERSE_PROXY_SETUP` set to `true`), although the attack potential is smaller there. This issue affects operators deploying ironic-image in the reverse proxy mode, which is the recommended mode when TLS is used (also recommended), with the `IRONIC_PRIVATE_PORT` variable unset or set to a numeric value. In this case, an attacker with enough privileges to launch a pod on the control plane with host networking can access Ironic API and use it to modify bare-metal machine, e.g. provision them with a new image or change their BIOS settings. This vulnerability is fixed in 24.1.1.