Add config_tempalte to collections

Since config_tempalte is really a handy module that can be used
outside of the OSA, we make it installable as collection and
start using it as a collection as well. This will also bring
us unambiguity about what exact module we use, since ceph-ansible
have their own interpritation of config_template that they ship.

Change-Id: Id52d56e387056066bfce28c781b24e8d98361ac5

ansible-collection-requirements.yml

@@ -2,6 +2,9 @@ collections:
   - name: https://opendev.org/openstack/ansible-collections-openstack
     version: 1.5.3
     type: git
+  - name: https://opendev.org/openstack/ansible-config_template
+    version: 1.2.1
+    type: git
   - name: https://github.com/ansible-collections/community.general
     version: 4.0.1
     type: git