Remove the stable/stein branch for Patrole

Patrole is branchless with "cycle-with-intermediary" model
and does not create the stable branch with same reason as
Tempest.

Below commit added the stable/stein for Patrole which is not
correct- https://review.opendev.org/#/c/650173

This commit removes the branching from stein patrole release.

As next step, we will add some type(as proposed by ttx[1]) or
tag to make it clear that Patrole does not need branch.

[1] https://review.opendev.org/#/c/670808/

Change-Id: Ib11838bc87e4fe0a350d107184be68e837233891

deliverables/stein/patrole.yaml

@@ -9,9 +9,6 @@ releases:
       - repo: openstack/patrole
         hash: 9cd0a43c19516c28a9937f79e9ff53bf87822160
     version: 0.5.0
-branches:
-  - location: 0.5.0
-    name: stable/stein
 repository-settings:
   openstack/patrole:
     pypi-name: Patrole