Remove task to delete overcloud stack

From wallaby we use ephemeral heat and there is no plan to
support upgrade from train to zed. This would remove the
unecessary usage of ansible-collections-openstack.

Change-Id: I67a4623370e66ec486e61ca5eaa2fb33baa8950a

tripleo_ansible/playbooks/cli-overcloud-delete.yaml

@@ -45,15 +45,6 @@
     - name: Delete OVN MAC Address ports
       tripleo_ovn_mac_addresses:
         stack_name: "{{ stack_name }}"
-    - name: Delete heat stack
-      openstack.cloud.stack:
-        name: "{{ stack_name }}"
-        state: absent
-      register: stack_delete
-      until: stack_delete is success
-      delay: 4
-      retries: 16
-      when: heat_stack_delete|default(false)
     - name: Remove the config download stack
       file:
         path: "{{ config_download_path }}/{{ stack_name }}"