Remove puppet-beaker-rspec-puppet-4-infra-system-config

This doesn't actually do anything useful any more, but it spends
a lot of time not doing it.

Basically, this is only testing the things in
modules/openstack_project/spec/acceptance/basic_spec.rb, which
are things we install and test in ansible now.

There are related jobs, puppet-beaker-rspec-puppet-4-infra,
which are run on puppet- repos and run their rspec tests, but
that won't be affected by this.

Change-Id: I21b01d360b50dba10673c2986e8a2868b8747522

.zuul.yaml

@@ -1,9 +1,3 @@
-- job:
-    name: puppet-beaker-rspec-puppet-4-infra-system-config
-    parent: puppet-beaker-rspec-puppet-4-infra
-    vars:
-      project_src_dir: "{{ zuul.project.src_dir }}/modules/openstack_project"
-
 # Image building jobs
 - secret:
     name: system-config-dockerhub
@@ -2149,7 +2143,6 @@
         - opendev-tox-docs
         - opendev-buildset-registry
         - tox-linters
-        - puppet-beaker-rspec-puppet-4-infra-system-config
         - system-config-run-base
         - system-config-run-base-ansible-devel:
             voting: false
@@ -2217,7 +2210,6 @@
         - opendev-tox-docs
         - opendev-buildset-registry
         - tox-linters
-        - puppet-beaker-rspec-puppet-4-infra-system-config
         - system-config-run-base
         - system-config-run-dns
         - system-config-run-eavesdrop