Fix run_puppet_on_*.yml files

Remove duplicated tasks line.

This is also reported when runnning: ansible-playbook --syntax-check.

Change-Id: Iad7b205418b57e6f38f2c4851ec2624a93689539

run_puppet_on_gerrit.yml

@@ -3,7 +3,6 @@
   user: ubuntu
   gather_facts: no
   sudo: true
-  tasks:
   name: Run Puppet to install Gerrit
   tasks:
     - puppet:

run_puppet_on_jenkins.yml

@@ -2,7 +2,6 @@
 - hosts: meta-infra_type_jenkins
   user: ubuntu
   sudo: true
-  tasks:
   name: Run Puppet to install Jenkins
   tasks:
     - puppet:

run_puppet_on_zuul.yml

@@ -3,7 +3,6 @@
   user: ubuntu
   gather_facts: no
   sudo: true
-  tasks:
   name: Run Puppet to install Zuul
   tasks:
     - puppet: