Remove jobs from project-config-example
Remove jobs from project-config-example

The repo project-config-example is showing a Zuul v2 config - and their
tests expect a Zuul v2 setup. Remove the legacy jobs since they do not
work anymore with zuul repository now at v3 - there's not much sense in
converting these jobs to native Zuul v3 syntax.

Change-Id: Icdadba3eceeefea160963ed59e371b0d79feb02f

openstack-infra/project-config,openstack-infra/project-config