CI: Install Apparmor

Docker 23.* is out and it started failing with apparmor_parser
related messages - it seems apparmor is missing in the OpenDev image.

Change-Id: I2a6d98e3c1d2d1b7c97a8e6172decbf56e77042d
(cherry picked from commit 16f27c5496)

tests/playbooks/pre.yml

@@ -51,6 +51,12 @@
           apt_repository:
             repo: "deb {{ nodepool_docker_proxy }}/{{ ansible_distribution | lower }} {{ ansible_distribution_release }} stable"
             state: present
+
+        - name: Ensure AppArmor is installed
+          package:
+            name: apparmor
+            state: present
+
       when: ansible_os_family == "Debian"
       become: true