Description of problem:
host evacuation fails for instances whom group instance get deleted

openstack server show reports for the error

{'code': 404, 'created': '2022-06-20T12:21:30Z', 'message': 'Instance group <instance group uuid> could not be found.'}

Version-Release number of selected component (if applicable):
OSP 16.2.0
OSP 16.2.1

How reproducible:
always

Steps to Reproduce:

• create an instance group
• create a vm with the previously instance group created
• delete the instance group previously created
• shutdown/reboot the compute where the instance it is running on
• evacuate the host with : nova host-evacuate <compute where Vm created belongs to>
  Actual results:

Expected results:
instance get evacuated

Additional info: