Removed unused infra spec helper job

This job ran on centos-7 which are are no longer testing. That means the
job can be removed.

Depends-On: https://review.opendev.org/715034
Change-Id: I2fdd01217d38bc73d241460359a9ce2e7d6b1687

playbooks/legacy/puppet-openstack-infra-spec-helper-unit-centos-7/run.yaml

@@ -1,49 +0,0 @@
-- hosts: all
-  name: Autoconverted job legacy-puppet-openstack-infra-spec-helper-unit-centos-7
-    from old job gate-puppet-openstack-infra-spec-helper-unit-centos-7
-  roles:
-    - bindep
-
-  tasks:
-
-    - name: Ensure legacy workspace directory
-      file:
-        path: '{{ ansible_user_dir }}/workspace'
-        state: directory
-
-    - shell:
-        cmd: |
-          /usr/zuul-env/bin/zuul-cloner --cache-dir /opt/git \
-              https://opendev.org opendev/puppet-openstack_infra_spec_helper
-        executable: /bin/bash
-        chdir: '{{ ansible_user_dir }}/workspace'
-      environment: '{{ zuul | zuul_legacy_vars }}'
-
-    - shell:
-        cmd: |
-          set -e
-          set -x
-          if [ -f /usr/bin/yum ]; then
-              sudo yum -y remove rdo-release "centos-release-openstack-*" "centos-release-ceph-*"
-              sudo yum -y install libxml2-devel libxslt-devel ruby-devel zlib-devel
-              sudo yum -y groupinstall "Development Tools"
-              # Uninstall python-requests from pip, since we install it in
-              # system-config/install_puppet.sh
-              sudo pip uninstall requests -y || true
-          elif [ -f /usr/bin/apt-get ]; then
-              sudo apt-get update
-              sudo apt-get install -y libxml2-dev libxslt-dev ruby-dev zlib1g-dev
-          fi
-        executable: /bin/bash
-        chdir: '{{ ansible_user_dir }}/workspace'
-      environment: '{{ zuul | zuul_legacy_vars }}'
-
-    - shell:
-        cmd: |
-          set -e
-          set -x
-          cd opendev/puppet-openstack_infra_spec_helper
-          ./run_unit_tests.sh
-        executable: /bin/bash
-        chdir: '{{ ansible_user_dir }}/workspace'
-      environment: '{{ zuul | zuul_legacy_vars }}'

zuul.d/zuul-legacy-jobs.yaml

@@ -573,15 +573,6 @@
     required-projects:
       - opendev/puppet-openstackci
 
-- job:
-    name: legacy-puppet-openstack-infra-spec-helper-unit-centos-7
-    parent: legacy-base
-    run: playbooks/legacy/puppet-openstack-infra-spec-helper-unit-centos-7/run.yaml
-    timeout: 3600
-    nodeset: legacy-centos-7
-    required-projects:
-      - opendev/puppet-openstackci
-
 - job:
     name: legacy-sandbox-tag
     parent: legacy-base