remove configuration files for ceph packages on ubuntu clusters

For apt-get, purge command needs to be used, instead of remove command,
to remove related configuration files. Otherwise, packages might be
shown as installed while running dpkg command even after removing them.

Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1640061
Signed-off-by: Rishabh Dave <ridave@redhat.com>

infrastructure-playbooks/purge-cluster.yml

@@ -566,6 +566,7 @@
     apt:
       name: "{{ item }}"
       state: absent
+      purge: true
     with_items: "{{ ceph_packages }}"
     when: ansible_pkg_mgr == 'apt'