Fix types on Bbox Wi-Fi 7

[angristan]

This fixes errors such as:

level=error ts=2025-06-21T14:53:47.591Z caller=exporter.go:88 msg="Bbox API error" err="LAN metrics: json: cannot unmarshal number into Go struct field .hosts.list.ethernet.speed of type string"

Looks like speed is a number on my bbox, and band can be a string or an int.

[stale]

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