Update jobs for Zed and disable auto discovery

The patch adds a yoga job as the upstream has just released it and
moved to the Zed development cycle.
The patch also disables autodiscovery to avoid the following bug with
setuptools 61.0.0 and possbile higher versions:
https://github.com/pypa/setuptools/issues/3197

Change-Id: I0f274a5a6746aa97614b08b4bb75f4731923a5ed

.zuul.yaml

@@ -4,6 +4,7 @@
       jobs:
         - openstack-tox-linters
         - refstack-client-devstack-master
+        - refstack-client-devstack-yoga
         - refstack-client-devstack-xena
         - refstack-client-devstack-wallaby
         - refstack-client-devstack-victoria
@@ -13,6 +14,7 @@
       jobs:
         - openstack-tox-linters
         - refstack-client-devstack-master
+        - refstack-client-devstack-yoga
         - refstack-client-devstack-xena
         - refstack-client-devstack-wallaby
         - refstack-client-devstack-victoria
@@ -82,6 +84,13 @@
     irrelevant-files:
       - ^.*\.md$
 
+- job:
+    name: refstack-client-devstack-yoga
+    parent: refstack-client-devstack-master
+    override-checkout: stable/yoga
+    vars:
+      branch: stable/yoga
+
 - job:
     name: refstack-client-devstack-xena
     parent: refstack-client-devstack-master

setup.py

@@ -16,4 +16,7 @@ import setuptools
 
 setuptools.setup(
     setup_requires=['pbr'],
+    # disable auto discovery to work around the following bug
+    # https://github.com/pypa/setuptools/issues/3197
+    py_modules=[],
     pbr=True)