mirror: Add centos-stream link

Missed this with I483c2982a6931e7d6fc97ab82f7750b72d2ef265; this
ensure the mirror webserver exports the directory.

Change-Id: I6e14cdace213a6af6df65b8ddb09bb3a167fbf9b

playbooks/roles/mirror/tasks/main.yaml

@@ -79,6 +79,7 @@
   with_items:
     - apt-puppetlabs
     - centos
+    - centos-stream
     - ceph-deb-nautilus
     - ceph-deb-octopus
     - deb-docker