Fix propose-final-releases command to use release-id

With the new release identification / naming schema [1] (like:
2023.1 Antelope) new stable branch naming was introduced (like:
stable/2023.1). This was not handled in the propose-final-releases command as
it still uses the release name. This patch fixes this by reading the
'release-id' field from series_status.yaml and if present then uses it
as stable/<release-id> for the branch creation.

[1] https://governance.openstack.org/tc/reference/release-naming.html

Change-Id: Ie8ba3e9bfa01148e93f5920050703e998248db11

openstack_releases/cmds/propose_final_releases.py

@@ -24,11 +24,26 @@ import tempfile
 import openstack_releases
 from openstack_releases import deliverable
 from openstack_releases import gitutils
+from openstack_releases import series_status
 from openstack_releases import yamlutils
 
 PRE_RELEASE = re.compile('(a|b|rc)')
 
 
+def get_stable_branch_id(series):
+    """Retrieve the stable branch ID of the series.
+
+    Returns the release-id if the series has such field, otherwise
+    returns the series name. This is needed for the new stable branch
+    naming style: stable/2023.1 (versus the old style: stable/zed).
+    """
+    series_status_data = series_status.SeriesStatus.default()
+    release_id = series_status_data[series].release_id
+    if release_id is None:
+        release_id = series
+    return str(release_id)
+
+
 def get_prior_branch_point(workdir, repo, branch):
     """Return the tag of the base of the branch.
 
@@ -180,7 +195,7 @@ def main():
             (latest_release.version.split('.')[:-1] + ['0'])[:3]
         )
 
-        branch = 'stable/{}'.format(args.prior_series)
+        branch = 'stable/{}'.format(get_stable_branch_id(args.prior_series))
         diff_start = get_prior_branch_point(
             workdir, projects[0].repo.name, branch,
         )