Redundant nmcli commands in documentation.

[mikerenfro]

https://github.com/XSEDE/CRI_XCBC/blob/9ac4e9f3731c94d5cf89c9b494892176dfdf266e/doc/README.md?plain=1#L166

These lines don't have to be run manually, since they're part of the pre_ohpc set of tasks. But we may need to adjust language here to ensure that the connections are named for the Ethernet devices. The Vagrant box for Rocky 8, at least, names them System eth0 and System eth1, and have to be renamed for the playbook to work correctly.