Update puppet jobs to default to puppet 4

This change removes the last of the puppet-3 puppet-apply jobs and
changes the default puppet version to '4' for the puppet-apply and
beaker jobs. This change leaves the unversioned base puppet jobs and the
puppet-4 child jobs even though they are now redundant for the sake of
clarity of the job ancestry.

Change-Id: I58a82d7e58ee1d2d8c653e4e92cab8cfc8d834b4

playbooks/infra-puppet-apply/run.yaml

@@ -7,6 +7,6 @@
       args:
         chdir: "{{ zuul.projects['opendev.org/opendev/system-config'].src_dir }}"
       environment:
-        PUPPET_VERSION: "{{ puppet_version | default('3') }}"
+        PUPPET_VERSION: "{{ puppet_version | default('4') }}"
       tags:
         - skip_ansible_lint

playbooks/infra-puppet-beaker-rspec/run.yaml

@@ -51,4 +51,4 @@
         chdir: "{{ project_src_dir }}"
       environment:
         'GEM_HOME': "{{ ansible_user_dir }}/.bundled_gems"
-        'PUPPET_VERSION': "{{ puppet_version | default('3') }}"
+        'PUPPET_VERSION': "{{ puppet_version | default('4') }}"

zuul.d/jobs.yaml

@@ -1452,17 +1452,6 @@
     run: playbooks/infra-puppet-apply/run.yaml
     post-run: playbooks/infra-puppet-apply/post.yaml
 
-- job:
-    name: infra-puppet-apply-3-ubuntu-xenial
-    parent: infra-puppet-apply-base
-    nodeset: ubuntu-xenial
-
-- job:
-    name: infra-puppet-apply-3-ubuntu-trusty
-    parent: infra-puppet-apply-base
-    nodeset: ubuntu-trusty
-    branches: master
-
 - job:
     name: infra-puppet-apply-4-ubuntu-xenial
     parent: infra-puppet-apply-base

zuul.d/project-templates.yaml

@@ -1574,12 +1574,10 @@
       Runs puppet apply tests for OpenStack Infrastructure.
     check:
       jobs:
-        - infra-puppet-apply-3-ubuntu-xenial
         - infra-puppet-apply-4-ubuntu-xenial
         - openstackci-beaker-puppet-4
     gate:
       jobs:
-        - infra-puppet-apply-3-ubuntu-xenial
         - infra-puppet-apply-4-ubuntu-xenial
         - openstackci-beaker-puppet-4