[congress] Transition Ussuri to EM

This transition the ussuri branch to extended maintenance.
Changes for bugfixes and things the team deems important are
still encouraged, but there will no longer be official releases
off of the branch.

Please +1 if the team is ready for us to proceed with this
transition, or -1 if there are any final backports currently in
flight that we should wait for. For the latter case, please
update the patch with the new commit hash after doing a final
release to get those changes out so we know to proceed with the
transition.

Change-Id: I3e5aa8de475f2c77110f9217eaa222c7f2a73156

deliverables/ussuri/congress-dashboard.yaml

@@ -16,6 +16,10 @@ releases:
       - repo: openstack/congress-dashboard
         hash: e298ddce8a91bb88a2b8ef15777eed02e23c7365
     diff-start: 5.0.0
+  - version: ussuri-em
+    projects:
+      - repo: openstack/congress-dashboard
+        hash: e298ddce8a91bb88a2b8ef15777eed02e23c7365
 branches:
   - name: stable/ussuri
     location: 6.0.0.0rc1

deliverables/ussuri/congress.yaml

@@ -16,6 +16,10 @@ releases:
       - repo: openstack/congress
         hash: 85243abf63dfc7c086e28e9bdb3fb0b7c9d2ad94
     diff-start: 10.0.0
+  - version: ussuri-em
+    projects:
+      - repo: openstack/congress
+        hash: 85243abf63dfc7c086e28e9bdb3fb0b7c9d2ad94
 branches:
   - name: stable/ussuri
     location: 11.0.0.0rc1

deliverables/ussuri/python-congressclient.yaml

@@ -15,6 +15,10 @@ releases:
     projects:
       - repo: openstack/python-congressclient
         hash: dc5aaeb84f9f31f8f9fbd360179974a879aa29f1
+  - version: ussuri-em
+    projects:
+      - repo: openstack/python-congressclient
+        hash: dc5aaeb84f9f31f8f9fbd360179974a879aa29f1
 branches:
   - name: stable/ussuri
     location: 2.0.1