Now you can install any iRODS version starting from 4.2.0

iRODS/tasks/packages.yml

@@ -8,7 +8,8 @@
     name: 
       - libselinux-python
       - python-pip
-      - irods-server
-      - irods-database-plugin-postgres
+      - irods-server-{{ irods_version }}
+      - irods-database-plugin-postgres-{{ irods_version }}
+    state: present
 
 ...