Remove pypy jobs

pypy jobs are non-voting and do not work. let's drop it
till someone fix the tool.

We so not run pypy jobs in other projects.

Change-Id: I6677bdda81253c94076a542a48b937224575cff4

.zuul.yaml

@@ -5,7 +5,6 @@
       - openstack-lower-constraints-jobs
       - openstack-python35-jobs
       - openstack-python3-ussuri-jobs
-      - openstack-pypy-jobs-nonvoting
       - release-notes-jobs-python3
     check:
       jobs: