Stop using os_stack module

This redirect does not work or won't work in the future.

Note: This adds ansible-core to test-requirements.txt,
we may need to add requirements.txt and ansible collections
in ansible-collections-requirements.yml in the future.

Change-Id: Iffb41b68283f77050d8073364156cc0aca85559e

roles/ovb-manage-stack/tasks/ovb-delete-stack.yml

@@ -12,7 +12,7 @@
     mode: 0755
 
 - name: Remove stack
-  os_stack:
+  openstack.cloud.stack:
     name: "{{ stack_name }}"
     cloud: "{{ cloud_name }}"
     state: absent

test-requirements.txt

@@ -1 +1,2 @@
+ansible-core>=2.11,<2.12
 jinja2

tox.ini

@@ -49,6 +49,7 @@ deps =
     jinja2
     pre-commit
 commands =
+    ansible-galaxy collection install -f openstack.cloud
     python -m pre_commit run -a
     # TODO(ssbarnea) make is a real pre-commit hook so we can reuse it
     python ci-scripts/validate_jinja2.py