docs: Override Wi-Fi in FIPS mode

Is there any way to override this specifically for WiFi? Users don't always have complete control over the networks they are connecting to, but that is why additional controls are added (e.g. VPN) to layer over the security of wifi.

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*Reported from: https://documentation.ubuntu.com/security/compliance/fips/how-to-enable-wifi/*

Start with the FIPS Wi-Fi documentation page linked in the issue and check how Wi-Fi restrictions are currently described. Determine whether an override is supported, then document the answer and any relevant VPN or network-control guidance; the page should clearly state what users can and cannot configure.

Written by the indexing model from the issue text.