Tests failing due to missing data file

When running the tests from the PyPI tarball, on openSUSE Tumbleweed, I get two failures looking for `ubuntu-artful.txt-distro-expected.json` in https://github.com/nexB/container-inspector/tree/main/tests/data/distro/os-release/ubuntu , but it doesnt exist.

This occurs irrespective of whether I add `/etc/os-release` from https://software.opensuse.org/package/openSUSE-release to the build VM.

```py
[ 32s] =================================== FAILURES ===================================
[ 32s] _________________ TestDistro.test_distro_from_os_release_file __________________
[ 32s]
[ 32s] self =
[ 32s]
[ 32s] def test_distro_from_os_release_file(self):
[ 32s] test_dir = self.get_test_loc('distro/os-release')
[ 32s]
[ 32s] for test_file in resource_iter(test_dir, with_dirs=False):
[ 32s] if test_file.endswith('-expected.json'):
[ 32s] continue
[ 32s] expected = test_file + '-distro-expected.json'
[ 32s] result = Distro.from_os_release_file(test_file).to_dict()
[ 32s] > check_expected(result, expected, regen=False)
[ 32s]
[ 32s] tests/test_distro.py:41:
[ 32s] _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
[ 32s]
[ 32s] result = {'architecture': None, 'bug_report_url': 'https://bugs.launchpad.net/ubuntu/', 'build_id': None, 'cpe_name': None, ...}
[ 32s] expected = '/home/abuild/rpmbuild/BUILD/container-inspector-32.0.1/tests/data/distro/os-release/ubuntu/ubuntu-artful.txt-distro-expected.json'
[ 32s] regen = False
[ 32s]
[ 32s] def check_expected(result, expected, regen=False):
[ 32s] """
[ 32s] Check equality between a result collection and an expected JSON file.
[ 32s] Regen the expected file if regen is True.
[ 32s] """
[ 32s] if regen:
[ 32s] with open(expected, 'w') as ex:
[ 32s] ex.write(json.dumps(result, indent=2))
[ 32s]
[ 32s] > with open(expected) as ex:
[ 32s] E FileNotFoundError: [Errno 2] No such file or directory: '/home/abuild/rpmbuild/BUILD/container-inspector-32.0.1/tests/data/distro/os-release/ubuntu/ubuntu-artful.txt-distro-expected.json'
[ 32s]
[ 32s] tests/utilities.py:21: FileNotFoundError
[ 32s] _______________________ TestDistro.test_parse_os_release _______________________
[ 32s]
[ 32s] self =
[ 32s]
[ 32s] def test_parse_os_release(self):
[ 32s] test_dir = self.get_test_loc('distro/os-release')
[ 32s]
[ 32s] for test_file in resource_iter(test_dir, with_dirs=False):
[ 32s] if test_file.endswith('expected.json'):
[ 32s] continue
[ 32s] expected = test_file + '-expected.json'
[ 32s] result = parse_os_release(test_file)
[ 32s] > check_expected(result, expected, regen=False)
[ 32s]
[ 32s] tests/test_distro.py:31:
[ 32s] _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _
[ 32s]
[ 32s] result = {'BUG_REPORT_URL': 'https://bugs.launchpad.net/ubuntu/', 'HOME_URL': 'https://www.ubuntu.com/', 'ID': 'ubuntu', 'ID_LIKE': 'debian', ...}
[ 32s] expected = '/home/abuild/rpmbuild/BUILD/container-inspector-32.0.1/tests/data/distro/os-release/ubuntu/ubuntu-artful.txt-expected.json'
[ 32s] regen = False
[ 32s]
[ 32s] def check_expected(result, expected, regen=False):
[ 32s] """
[ 32s] Check equality between a result collection and an expected JSON file.
[ 32s] Regen the expected file if regen is True.
[ 32s] """
[ 32s] if regen:
[ 32s] with open(expected, 'w') as ex:
[ 32s] ex.write(json.dumps(result, indent=2))
[ 32s]
[ 32s] > with open(expected) as ex:
[ 32s] E FileNotFoundError: [Errno 2] No such file or directory: '/home/abuild/rpmbuild/BUILD/container-inspector-32.0.1/tests/data/distro/os-release/ubuntu/ubuntu-artful.txt-expected.json'
[ 32s]
[ 32s] tests/utilities.py:21: FileNotFoundError
```