[OpenStackSDK] Create for all client and non-client lib xena branch

This creates the stable/xena branch for all client
and non-client libraries now that we are past the
lib freeze on September 02.

If a team wants to wait for a specific patch to make it to the library,
someone from the team can -1 the patch to have it held,or update that
patch with a different commit SHA.

Patches with no response will be merged by Friday, September 10.

Change-Id: Ic32e61ce97fef189ecf65acb5ddc9676ee4052eb

deliverables/xena/cliff.yaml

@@ -15,3 +15,6 @@ releases:
     projects:
       - repo: openstack/cliff
         hash: 734bc0c5da6915f10823a3124e08ba3ddbd4cc63
+branches:
+  - name: stable/xena
+    location: 3.9.0

deliverables/xena/openstacksdk.yaml

@@ -27,3 +27,5 @@ branches:
   - name: feature/r1
     location:
       openstack/openstacksdk: b38e7173e237e986f3acf60449c97fbe56a16cd5
+  - name: stable/xena
+    location: 0.59.0

deliverables/xena/osc-lib.yaml

@@ -19,3 +19,6 @@ releases:
     projects:
       - repo: openstack/osc-lib
         hash: 415a6c7b191ac665fb7763d12d1b427b7b630586
+branches:
+  - name: stable/xena
+    location: 2.4.2