Add ensure-pip to quick-start job

We assume pip exists and were getting it from opendev images before.
Add ensure-pip so that pip exists.

Depends-On: https://review.opendev.org/735904
Change-Id: Ifbd32f11f09c518062ffa350f9ebbe597493df67

playbooks/quick-start/run.yaml

@@ -6,6 +6,7 @@
     - name: ensure-docker
       use_upstream_docker: false
       docker_compose_install: true
+    - ensure-pip
     - use-buildset-registry
   tasks:
     - name: Install git-review