Drop baremetal job template

https://review.openstack.org/#/c/619337/ switched the jobs to a noop for
master and since this file is branched we no longer need to keep this
template definition in this project.

Change-Id: Ie35f87c3c6e0a5cc0da9a4dbe80faa2c5d9fb714

zuul.d/layout.yaml

@@ -18,7 +18,6 @@
       - puppet-openstack-check-jobs
       - puppet-tripleo-module-unit-jobs
       - tripleo-undercloud-jobs
-      - tripleo-multinode-baremetal-minimal
       - tripleo-multinode-container-minimal
       - release-notes-jobs-python3
     check: