Introduce cycle-automatic release model

For things like tempest-plugins, the cycle-with-intermediary model
is a bit overkill, especially now that we encourage multiple
intermediary releases to qualify.

Introduce a new 'cycle-automatic' model for deliverables that only
need to be released once, automatically at the end of the cycle.
This is limited to "other" or "tempest-plugin" deliverables.

Task: 31025
Change-Id: I83ff63cef18ae297013c3761a373078e580cf58b

doc/source/reference/process.rst

@@ -266,6 +266,9 @@ RC1 week
    someone from the team can -1 the patch to have it held, or update
    that patch with a different commit SHA.
 
+#. Generate release requests (without ``stable/$series`` branch creation)
+   for all cycle-automatic deliverables.
+
 #. By the end of the week, ideally we would want a +1 from the PTL and/or
    release liaison to indicate approval. However we will consider the absence
    of -1 or otherwise negative feedback as an indicator that the automatically

doc/source/reference/release_models.rst

@@ -117,6 +117,22 @@ release until OpenStack itself is released.
 * Release tags for deliverables using this tag are reviewed and
   applied by the Release Management team.
 
+.. _cycle-automatic:
+
+cycle-automatic
+===============
+
+The "cycle-automatic" model is used by specific technical deliverables
+that just need to be automatically released once (and only once) at the
+end of a cycle. Those do not need a stable branch created. This may be
+applied only to "tempest-plugin" or "other" deliverables.
+
+* "cycle-automatic" deliverables will be automatically released by the
+  release team once at the end of a cycle, using the current HEAD of the
+  repository. No stable branch will be automatically created.
+* Release tags for deliverables using this model are reviewed and
+  applied by the Release Management team.
+
 .. _independent:
 
 independent

openstack_releases/schema.yaml

@@ -30,7 +30,7 @@ properties:
     type: "boolean"
   release-model:
     type: "string"
-    enum: ["cycle-with-intermediary", "cycle-with-milestones", "cycle-trailing", "untagged", "cycle-with-rc"]
+    enum: ["cycle-with-intermediary", "cycle-with-milestones", "cycle-trailing", "untagged", "cycle-with-rc", "cycle-automatic"]
   type:
     type: "string"
     enum: ["horizon-plugin", "library", "client-library", "service", "tempest-plugin", "other"]