Revert "Reapply "Select the network to use in raxflex""

This reverts commit 2d6961a0f7.

We think we've tracked down why this wasn't working before and the
depends-on should have us back to using the configuration the
zuul-provider repo. Once that lands we can land this change then restart
launchers to pick up this config update to clouds.yaml

Depends-On: https://review.opendev.org/c/opendev/zuul-providers/+/962235
Change-Id: Ic7d21da980f62f285c3ab15302bd914e037798da

playbooks/templates/clouds/zuul_clouds.yaml.j2

@@ -63,10 +63,6 @@ clouds:
           metrics:
             statsd:
               prefix: 'openstacksdk.zuul-launcher.task.raxflex-iad3'
-    networks:
-      - name: opendevzuul-network1
-        default_interface: true
-        nat_destination: true
     auth:
       auth_url: 'https://keystone.api.{region_name}.rackspacecloud.com/v3'
       project_id: '{{ zuul_rax_flex_project }}'