fix the group for bertptrs

He was onboarded as a Junior Packager but mistakenly the wrong group was
assigned to him.

Fixes: 27a2c9ac ("Onboard bertptrs as Junior Package Maintainer")
Signed-off-by: Christian Heusel <christian@heusel.eu>

group_vars/all/archusers.yml

@@ -180,7 +180,7 @@ arch_users:
     email: "bertptrs@archlinux.org"
     ssh_key: bertptrs_ganymede.pub
     groups:
-      - packager
+      - junior-packager
     additional_ssh_keys:
       - name: bertptrs_rhea.pub
         hosts: all