dashboard: remove cfg80211 module installation

dashboard: remove cfg80211 module installation

According to this comment [1], this seems to be needed to detect wifi
devices.

In node exporter we can see this:

```
--collector.wifi          Enable the wifi collector (default: disabled).
```

since it's enabled by default and we don't even change this in our
systemd templates for node-exporter, we can easily assume in the end
it's not needed. Therefore, let's remove this.

[1] https://github.com/ceph/ceph-ansible/commit/dbf81b6b5bd6d7e977706a93f9e75b38efe32305#diff-961545214e21efed3b84a9e178927a08L21-L23

Signed-off-by: Guillaume Abrioux <gabrioux@redhat.com>
(cherry picked from commit b9cdf341beaf5a83bf5eec3b64c2c29ee78185ac)