Add Python3 project templates for Zed release

TC has defined the python testing runtime[1] and this
commit defines the job template to be used for testing the
defined testing runtime for Zed release[1].

This also defines openstack-python3-zed-jobs-arm64 template
which is needed to continue the arms64 testing as n-v
for many projects like Nova, Cinder, Heat etc.

[1] https://governance.openstack.org/tc/reference/runtimes/zed.html

Change-Id: I84e5b758b087eac0fe59b4683cbc1ab86535b77b

zuul.d/project-templates.yaml

@@ -538,6 +538,124 @@
         - openstack-tox-py38
         - openstack-tox-py39
 
+- project-template:
+    name: openstack-python3-zed-jobs
+    description: |
+      Runs unit tests for an OpenStack Python project under the CPython
+      version 3 releases designated for testing in the Zed release.
+    check:
+      jobs:
+        - openstack-tox-pep8
+        - openstack-tox-py38
+        - openstack-tox-py39
+    gate:
+      jobs:
+        - openstack-tox-pep8
+        - openstack-tox-py38
+        - openstack-tox-py39
+    post:
+      jobs:
+        - publish-openstack-python-branch-tarball
+
+- project-template:
+    name: openstack-python3-zed-jobs-horizon
+    description: |
+      The standard :zuul:project_template:`openstack-python3-zed-jobs`
+      but with horizon added as a required-projects. This checks out
+      the project code and allows tox_install_siblings to use horizon
+      when building the venv.
+    check:
+      jobs:
+        - openstack-tox-pep8:
+            required-projects:
+              - openstack/horizon
+        - openstack-tox-py38:
+            required-projects:
+              - openstack/horizon
+        - openstack-tox-py39:
+            required-projects:
+              - openstack/horizon
+    gate:
+      jobs:
+        - openstack-tox-pep8:
+            required-projects:
+              - openstack/horizon
+        - openstack-tox-py38:
+            required-projects:
+              - openstack/horizon
+        - openstack-tox-py39:
+            required-projects:
+              - openstack/horizon
+    post:
+      jobs:
+        - publish-openstack-python-branch-tarball
+
+- project-template:
+    name: openstack-python3-zed-jobs-neutron
+    description: |
+      The standard :zuul:project_template:`openstack-python3-zed-jobs`
+      but with neutron added as a required-projects. This checks out
+      the project code and allows tox_install_siblings to use neutron
+      when building the venv.
+    check:
+      jobs:
+        - openstack-tox-pep8:
+            required-projects:
+              - openstack/neutron
+        - openstack-tox-py38:
+            required-projects:
+              - openstack/neutron
+        - openstack-tox-py39:
+            required-projects:
+              - openstack/neutron
+    gate:
+      jobs:
+        - openstack-tox-pep8:
+            required-projects:
+              - openstack/neutron
+        - openstack-tox-py38:
+            required-projects:
+              - openstack/neutron
+        - openstack-tox-py39:
+            required-projects:
+              - openstack/neutron
+    post:
+      jobs:
+        - publish-openstack-python-branch-tarball
+
+- project-template:
+    name: openstack-python3-zed-jobs-ceilometer
+    description: |
+      The standard :zuul:project_template:`openstack-python3-zed-jobs`
+      but with ceilometer added as a required-projects. This checks out
+      the project code and allows tox_install_siblings to use ceilometer
+      when building the venv.
+    check:
+      jobs:
+        - openstack-tox-pep8:
+            required-projects:
+              - openstack/ceilometer
+        - openstack-tox-py38:
+            required-projects:
+              - openstack/ceilometer
+        - openstack-tox-py39:
+            required-projects:
+              - openstack/ceilometer
+    gate:
+      jobs:
+        - openstack-tox-pep8:
+            required-projects:
+              - openstack/ceilometer
+        - openstack-tox-py38:
+            required-projects:
+              - openstack/ceilometer
+        - openstack-tox-py39:
+            required-projects:
+              - openstack/ceilometer
+    post:
+      jobs:
+        - publish-openstack-python-branch-tarball
+
 - project-template:
     name: openstack-python3-yoga-jobs
     description: |
@@ -939,6 +1057,21 @@
       jobs:
         - publish-openstack-python-branch-tarball
 
+- project-template:
+    name: openstack-python3-zed-jobs-arm64
+    description: |
+      Runs unit tests for an OpenStack Python project under the CPython
+      version 3 releases designated for testing in the Zed release
+      on top of ARM64 architecture. This currently runs only a limited
+      test set and supplements the python3-zed-jobs. And it should
+      not be run instead of the default!
+    check-arm64:
+      jobs:
+        - openstack-tox-py38-arm64:
+            voting: false
+        - openstack-tox-py39-arm64:
+            voting: false
+
 - project-template:
     name: openstack-python3-yoga-jobs-arm64
     description: |