Remove ssh key in base cleanup run.

If the builds ssh key is removed during post run no cleanup
actions can be made on remote hosts by jobs inheriting from
the base job. It also causes problems with ssh keys
not being removed for static nodes when jobs are aborted.

Change-Id: Id751e8a842ed0d03e605dcd0620c388c3d7f973b

playbooks/base/cleanup.yaml

@@ -0,0 +1,3 @@
+- hosts: all
+  roles:
+    - remove-build-sshkey

playbooks/base/post.yaml

@@ -1,10 +1,3 @@
 - hosts: all
   roles:
     - fetch-output
-
-- hosts: all
-  # NOTE(pabelanger): We ignore_errors for the following tasks as not to fail
-  # successful jobs.
-  ignore_errors: yes
-  roles:
-    - remove-build-sshkey

zuul.yaml

@@ -11,6 +11,7 @@
       It also sets a default timeout value (which may be overidden).
     pre-run: playbooks/base/pre.yaml
     post-run: playbooks/base/post.yaml
+    cleanup-run: playbooks/base/cleanup.yaml
     roles:
       - zuul: opendev.org/zuul/zuul-jobs
     timeout: 1800