Overcloud deployment or upgrade prepare fails due to AttributeError: 'NoneType' object has no attribute 'keys'

Issue

• openstack overcloud deploy or openstack overcloud upgrade prepare fails with AttributeError: 'NoneType' object has no attribute 'keys' error.

  2023-09-15 09:54:39.643 150830 WARNING tripleoclient.v1.overcloud_deploy.DeployOvercloud [-] rendering j2 template to file: /home/stack/overcloud-deploy/overcloud/tripleo-heat-templates/puppet/controller-role.yaml
  2023-09-15 09:54:39.643 150830 WARNING tripleoclient.v1.overcloud_deploy.DeployOvercloud [-] rendering j2 template to file: /home/stack/overcloud-deploy/overcloud/tripleo-heat-templates/puppet/compute-role.yaml
  /usr/lib/python3.9/site-packages/heatclient/common/template_utils.py:206: DeprecationWarning: Using or importing the ABCs from 'collections' instead of from 'collections.abc' is deprecated since Python 3.3, and in 3.10 it will stop working 
    if isinstance(v, collections.Mapping):
  2023-09-15 09:54:42.962 150830 ERROR tripleoclient.v1.overcloud_deploy.DeployOvercloud [-] Exception occured while running the command: AttributeError: 'NoneType' object has no attribute 'keys'
  2023-09-15 09:54:42.962 150830 ERROR tripleoclient.v1.overcloud_deploy.DeployOvercloud Traceback (most recent call last):
  2023-09-15 09:54:42.962 150830 ERROR tripleoclient.v1.overcloud_deploy.DeployOvercloud   File "/usr/lib/python3.9/site-packages/tripleoclient/command.py", line 32, in run
  2023-09-15 09:54:42.962 150830 ERROR tripleoclient.v1.overcloud_deploy.DeployOvercloud     super(Command, self).run(parsed_args)
  2023-09-15 09:54:42.962 150830 ERROR tripleoclient.v1.overcloud_deploy.DeployOvercloud   File "/usr/lib/python3.9/site-packages/osc_lib/command/command.py", line 39, in run
  2023-09-15 09:54:42.962 150830 ERROR tripleoclient.v1.overcloud_deploy.DeployOvercloud     return super(Command, self).run(parsed_args)
  2023-09-15 09:54:42.962 150830 ERROR tripleoclient.v1.overcloud_deploy.DeployOvercloud   File "/usr/lib/python3.9/site-packages/cliff/command.py", line 186, in run 
  2023-09-15 09:54:42.962 150830 ERROR tripleoclient.v1.overcloud_deploy.DeployOvercloud     return_code = self.take_action(parsed_args) or 0
  2023-09-15 09:54:42.962 150830 ERROR tripleoclient.v1.overcloud_deploy.DeployOvercloud   File "/usr/lib/python3.9/site-packages/tripleoclient/v1/overcloud_deploy.py", line 1161, in take_action
  2023-09-15 09:54:42.962 150830 ERROR tripleoclient.v1.overcloud_deploy.DeployOvercloud     created_env_files = self.create_env_files(
  2023-09-15 09:54:42.962 150830 ERROR tripleoclient.v1.overcloud_deploy.DeployOvercloud   File "/usr/lib/python3.9/site-packages/tripleoclient/v1/overcloud_deploy.py", line 261, in create_env_files
  2023-09-15 09:54:42.962 150830 ERROR tripleoclient.v1.overcloud_deploy.DeployOvercloud     utils.check_prohibited_overrides(protected_overrides,
  2023-09-15 09:54:42.962 150830 ERROR tripleoclient.v1.overcloud_deploy.DeployOvercloud   File "/usr/lib/python3.9/site-packages/tripleoclient/utils.py", line 2916, in check_prohibited_overrides
  2023-09-15 09:54:42.962 150830 ERROR tripleoclient.v1.overcloud_deploy.DeployOvercloud     registry = set(data.get('resource_registry', {}).keys())
  2023-09-15 09:54:42.962 150830 ERROR tripleoclient.v1.overcloud_deploy.DeployOvercloud AttributeError: 'NoneType' object has no attribute 'keys'
  2023-09-15 09:54:42.962 150830 ERROR tripleoclient.v1.overcloud_deploy.DeployOvercloud
  2023-09-15 09:54:43.011 150830 ERROR openstack [-] 'NoneType' object has no attribute 'keys'
  2023-09-15 09:54:43.011 150830 INFO osc_lib.shell [-] END return value: 1