Remove post-run playbooks from child doc publishing jobs

The abstract base docs publication job already defines the post.yaml
then publish.yaml playbooks for these jobs. That order is important
because we need post.yaml to fetch the sphinx output before we run
publish.yaml. However, when we set post-run to publish.yaml in the child
jobs that means publish.yaml runs first and fails. Then we continue to
run the parent playbooks in the right order (post.yaml then
publish.yaml) and successfully update docs. But at this point we've
already recorded the job as a failure.

Fix this erroneous failure mode by removing the post-run publish.yaml
playbook from the child jobs. We can just let the parent defs run and
that should ensure the correct order.

Change-Id: I0102c0fa2af437cedc129e2fe587ac4314d593e3

zuul.d/nox-jobs.yaml

@@ -83,7 +83,6 @@
       only a single branch and multiple version-specific copies of
       its documentation are undesirable, or when triggered by a tag
       alongside a version-specific publication job.
-    post-run: playbooks/nox-docs/publish.yaml
     secrets:
       - secret: opendev-unversioned-docs
         name: afs
@@ -97,7 +96,6 @@
 
       Use this in the tag or release pipelines to publish a build
       based on a newly-created tag.
-    post-run: playbooks/nox-docs/publish.yaml
     secrets:
       - secret: opendev-zuul-docs
         name: afs

zuul.d/tox-jobs.yaml

@@ -83,7 +83,6 @@
       only a single branch and multiple version-specific copies of
       its documentation are undesirable, or when triggered by a tag
       alongside a version-specific publication job.
-    post-run: playbooks/tox-docs/publish.yaml
     secrets:
       - secret: opendev-unversioned-docs
         name: afs
@@ -97,7 +96,6 @@
 
       Use this in the tag or release pipelines to publish a build
       based on a newly-created tag.
-    post-run: playbooks/tox-docs/publish.yaml
     secrets:
       - secret: opendev-zuul-docs
         name: afs