Update jobs for opendev tenant

As git-review has moved to the "opendev" tenant in OpenDev's Zuul
now, update its jobs to still work there and re-add release jobs
based on similar configuration for the opendev/bindep repository.

Change-Id: I7700ca9369080138122829ab2d4ddf3bbaea7b5f
Depends-On: https://review.opendev.org/777774

.zuul.yaml

@@ -1,8 +1,12 @@
 - project:
+    vars:
+      release_python: python3
     templates:
-      - publish-tox-docs-infra
+      - publish-opendev-tox-docs
     check:
       jobs: &jobs
+        - build-python-release:
+            nodeset: ubuntu-focal
         - tox-linters
         - tox-py35:
             nodeset: ubuntu-xenial
@@ -13,3 +17,10 @@
             nodeset: ubuntu-focal
     gate:
       jobs: *jobs
+    promote:
+      jobs:
+        - opendev-promote-python
+    release:
+      jobs:
+        - opendev-release-python:
+            nodeset: ubuntu-focal