roles/docker_compose/tasks/main.yml - enable docker buildkit

So that COPY --chmod works, which is useful for an ansible copy which
doesn't preserve permissions.

roles/docker_compose/tasks/main.yml

@@ -47,6 +47,9 @@
         "log-driver": "json-file",
         "log-opts": {
           "max-size": "30m"
+        },
+        "features": {
+          "buildkit": true
         }
       }
   notify: