Add golang based docker compose tool.

This installs the golang based compose (v2) tool.  Also make it the
python based tool optional, but installed by default.

The docker compose v2 tool comes from either:
 - Disrto   : Moby Engine : docker-compose-v2     : Focal -> Oracular
 - Upstream : Docker Inc  : docker-compose-plugin : Trusty -> Noble

With manual checking I can't see any distro older than focal that makes
use of the install-docker role, and all in-tree users pull from
upstream, so I think adding the golang compose tool without checking
the release is safe.

Change-Id: Ib8b5af40e626cd2d1a12b643f348001b9fdf4586

playbooks/roles/install-docker/defaults/main.yaml

@@ -1,2 +1,3 @@
 use_upstream_docker: True
 docker_update_channel: stable
+with_python_compose: True

playbooks/roles/install-docker/tasks/distro.yaml

@@ -1,5 +1,7 @@
 - name: Install docker
   become: yes
   package:
-    name: docker.io
+    name:
+      - docker.io
+      - docker-compose-v2
     state: present

playbooks/roles/install-docker/tasks/main.yaml

@@ -34,11 +34,14 @@
       - libssl-dev
     state: present
 
-- name: ensure pip3 is installed
+- name: Install python docker-compose if needed
+  when: with_python_compose|bool
+  block:
+  - name: ensure pip3 is installed
     include_role:
       name: pip3
 
-- name: Install docker-compose
+  - name: Install docker-compose
     pip:
       name:
         # The explicit pin of requests is a temporary workaround to getting

playbooks/roles/install-docker/tasks/upstream.yaml

@@ -49,6 +49,8 @@
 - name: Install docker
   become: yes
   apt:
-    name: docker-ce
+    name:
+      - docker-ce
+      - docker-compose-plugin
     state: present
     update_cache: yes