Set python interpreter for connection:local plays

These are the last two remaining 'connection: local' plays.
We set the python interpreter to be used as the host instead
of the Ansible venv. This resolves the issue with the venv
being python3 but the playbook modules requiring python2
libraries.

Change-Id: Ib4726afbaad1e084e9126202706114bfec5585c2

scripts/upgrade-utilities/playbooks/ansible_fact_cleanup.yml

@@ -23,3 +23,4 @@
       command: "{{ upgrade_scripts }}/ansible_fact_cleanup.sh"
   vars:
       upgrade_scripts: "{{ playbook_dir }}/../scripts"
+      ansible_python_interpreter: "/usr/bin/python"

tests/get-ansible-role-requirements.yml

@@ -114,6 +114,7 @@
         - _zuul_cloner_check.rc == 0
 
   vars:
+    ansible_python_interpreter: "/usr/bin/python"
     roles: "{{ lookup('file', role_file) | from_yaml }}"
     role_file: '../ansible-role-requirements.yml'
     role_path_default: '/etc/ansible/roles'