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] dbf81b6b5b (diff-961545214e21efed3b84a9e178927a08L21-L23)

Signed-off-by: Guillaume Abrioux <gabrioux@redhat.com>
(cherry picked from commit b9cdf341be)

roles/ceph-node-exporter/tasks/setup_container.yml

@@ -7,11 +7,6 @@
     group: root
     mode: 0644
 
-- name: add the cfg80211 module
-  modprobe:
-    name: cfg80211
-    state: present
-
 - name: start the node_exporter service
   systemd:
     name: node_exporter