To Reproduce Steps to reproduce the behavior:

1. Create an instance of the observabilityclient using the python client
2. Query the observabilyclient instance (e.g. c.query().list())
3. See that "HOME" is not defined (https://github.com/openstack/python-observabilityclient/blob/cda93078a081209dbebd434397d5523c256e6cbe/observabilityclient/utils/metric_utils.py#L23)

Expected behavior

• The query should be executed correctly