IAM: Retry cloudformation by deleting it

fixes:

The error was: botocore.exceptions.ClientError: An error occurred (ValidationError) when calling the UpdateStack operation: Stack
:arn:aws:cloudformation:us-east-1:...:stack/roles/... in ROLLBACK_COMPLETE state and can not be updated.

playbooks/roles/infra-aws-sandbox/tasks/iam.yml

@@ -5,6 +5,7 @@
     template_body: "{{ lookup('file', 'CF-IAM.json') }}"
     region: "{{ aws_region }}"
     stack_name: roles
+    on_create_failure: DELETE
   register: _cfiamrole
   until: _cfiamrole is succeeded
   delay: 60