Ensure CentOS nodes are selinux Permissive

CentOS 9 nodes are startng with selinux in
Enforcing mode. This is not the expected
configuration to run RDO/CentOS tests.

This patch sets selinux to permissive in pre
when running on CentOS.

Change-Id: I14dff0c0bb2d793ef4cd52ddcc2ff5ca4f870b97
Related-Bug: #1998954

roles/prepare-node/tasks/main.yaml

@@ -66,3 +66,11 @@
         value: '0 2147483647'
         state: present
         sysctl_file: /etc/sysctl.d/99-workarounds.conf
+
+# Reference: https://bugs.launchpad.net/tripleo/+bug/1998954
+- name: Ensure CentOS runs with selinux permissive
+  become: true
+  selinux:
+    policy: targeted
+    state: permissive
+  when: ansible_distribution == 'CentOS'