Bump openstacksdk to >1

This patch also vendors the openstack.cloud.subnet
module due to a problem with `disable_gateway_ip`
not being set for newly created subnets[1].

[1]: https://review.opendev.org/c/openstack/ansible-collections-openstack/+/940927

Change-Id: Ia021a1d7b82823c2e7498fdd66da3e2d5c6a8a79
(cherry picked from commit 8ccabb61cb8aa6a86c653cc47e43a648e8e07268)
diff --git a/roles/neutron/tasks/main.yml b/roles/neutron/tasks/main.yml
index 874ed3c..2331880 100644
--- a/roles/neutron/tasks/main.yml
+++ b/roles/neutron/tasks/main.yml
@@ -87,7 +87,7 @@
       until: _result is not failed
 
     - name: Create subnets
-      openstack.cloud.subnet:
+      vexxhost.atmosphere.subnet:
         cloud: atmosphere
         # Subnet settings
         network_name: "{{ item.0.name }}"