Problem Description: test_pulp_roles_endpoint in galaxy_ng/tests/integration/api/test_pulp_api.py contains a hard coded pulp_href.

Proposed Solution: url should be formed using the api_prefix variable

https://github.com/ansible/galaxy_ng/blob/master/galaxy_ng/tests/integration/api/test_pulp_api.py#L103

Reminders:

• Set the affected Component(s): Backend, Infrastructure, Pulp, QE, Security, UI
• Apply labels "crc-automation-hub" and/or "private-automation-hub" to indicate if the issue is for Cloud Automation Hub, Private Automation Hub, or both