Pin python3-pluggy back

The package is included in Caracal UCA repo but requires newer
python3-pytest which is not present in UCA and causes a conflict [1]
Corresponsive bug report was created towards UCA [2], but until then
it's worth to pin package back to be installed from universe rather then
UCA.

[1] https://paste.openstack.org/show/b9gCyKaVHjYMeupI5dLD/
[2] https://bugs.launchpad.net/cloud-archive/+bug/2064798

Change-Id: I47e796648a820927b79794110d07a9ce88d98cc2

defaults/main.yml

@@ -198,6 +198,10 @@ openstack_hosts_apt_pinned_packages:
   - package: "src:ceph"
     origin: "ubuntu-cloud.archive.canonical.com"
     priority: 400
+  # NOTE(noonedeadpunk): Remove once https://bugs.launchpad.net/cloud-archive/+bug/2064798 sorted out
+  - package: "python3-pluggy"
+    release: Canonical,n={{ ansible_facts['lsb']['codename'] }}-updates/{{ openstack_distrib_code_name | lower }}
+    priority: 400
 
 # Define extra systemd services/networks/mounts
 openstack_hosts_systemd_mounts: []