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/galaxy.yml b/galaxy.yml
index 6bcc5c3..886bc97 100644
--- a/galaxy.yml
+++ b/galaxy.yml
@@ -15,7 +15,7 @@
   community.general: 7.3.0
   community.mysql: 3.6.0
   kubernetes.core: 2.4.0
-  openstack.cloud: 1.7.0
+  openstack.cloud: ">=2.0.0"
   vexxhost.ceph: 3.0.1
   vexxhost.kubernetes: ">=2.0.1"
 tags: