Update zuul ansible installs when restarting zuul

This change adds a task to the zuul restart playbook to update the zuul
ansible installs on the executors during the restart. This will help
ensure we keep our ansible installs there up to date.

Change-Id: I443e204eaa69dcf0c5622303201549224e893626

playbooks/zuul_restart.yaml

@@ -97,6 +97,10 @@
         path: /var/run/zuul/executor.pid
         state: absent
         timeout: 11400
+    - name: Update the ansible installations
+      command: zuul-manage-ansible -u
+      environment:
+        ANSIBLE_EXTRA_PACKAGES: gear
     - name: Start Zuul Executors
       service:
         name: zuul-executor