Retire openstack/faafo

This repo was part of the first-app document that was retired last year
as part of the api-site retirement work.

Start the retirement of openstack/faafo with adding noop-jobs to the
repo.

Retirement announcement:
http://lists.openstack.org/pipermail/openstack-discuss/2020-March/012925.html

Needed-By: https://review.opendev.org/710653
Change-Id: I84da8c57d1e21f6662fcd805562225e715e803ec

zuul.d/projects.yaml

@@ -1723,13 +1723,7 @@
 - project:
     name: openstack/faafo
     templates:
-      - publish-openstack-docs-pti
-    check:
-      jobs:
-        - openstack-tox-pep8
-    gate:
-      jobs:
-        - openstack-tox-pep8
+      - noop-jobs
 
 - project:
     name: openstack/freezer