Centralize and manage multiple administrator SSH public keys for server access and streamline administrative tasks.
This change:
- Allows provisioning of multiple admin SSH keys to the `iklim` user for human access.
- Adds the same admin SSH keys to the `root` user for emergency or bootstrap scenarios.
- Grants the `iklim` user passwordless sudo privileges to simplify administrative operations.
- Replaces the single `admin_ssh_public_key_path` variable with a list of keys, accommodating multiple administrators.