cyborg-tempest-ipv6-only (non-voting) is failing a tempest tests with AttributeError: module 'tempest.test' has no attribute 'attr'

cyborg-tempest-ipv6-only (non-voting) is failing a tempest tests with AttributeError: module 'tempest.test' has no attribute 'attr', Below is the traceback
```
2026-01-29 20:14:48.896884 | controller | all run-test: commands[0] | find . -type f -name '*.pyc' -delete
2026-01-29 20:14:49.173380 | controller | all run-test: commands[1] | tempest run --regex cyborg_tempest_plugin --concurrency=6
2026-01-29 20:14:54.292344 | controller |
2026-01-29 20:14:54.292419 | controller | =========================
2026-01-29 20:14:54.292434 | controller | Failures during discovery
2026-01-29 20:14:54.292445 | controller | =========================
2026-01-29 20:14:54.292457 | controller | --- import errors ---
2026-01-29 20:14:54.292478 | controller | Failed to import test module: cyborg_tempest_plugin.tests.api.test_accelerator_request_negative
2026-01-29 20:14:54.292502 | controller | Traceback (most recent call last):
2026-01-29 20:14:54.292527 | controller | File "/usr/lib/python3.12/unittest/loader.py", line 394, in _find_test_path
2026-01-29 20:14:54.292544 | controller | module = self._get_module_from_name(name)
2026-01-29 20:14:54.292605 | controller | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2026-01-29 20:14:54.292619 | controller | File "/usr/lib/python3.12/unittest/loader.py", line 337, in _get_module_from_name
2026-01-29 20:14:54.292631 | controller | __import__(name)
2026-01-29 20:14:54.292642 | controller | File "/opt/stack/tempest/.tox/tempest/lib/python3.12/site-packages/cyborg_tempest_plugin/tests/api/test_accelerator_request_negative.py", line 23, in <module>
2026-01-29 20:14:54.292655 | controller | class AcceleratorRequestNegativeTest(base.BaseAPITest):
2026-01-29 20:14:54.292666 | controller | File "/opt/stack/tempest/.tox/tempest/lib/python3.12/site-packages/cyborg_tempest_plugin/tests/api/test_accelerator_request_negative.py", line 31, in AcceleratorRequestNegativeTest
2026-01-29 20:14:54.292711 | controller | @test.attr(type=['negative', 'gate'])
2026-01-29 20:14:54.292724 | controller | ^^^^^^^^^
2026-01-29 20:14:54.292736 | controller | AttributeError: module 'tempest.test' has no attribute 'attr'
2026-01-29 20:14:54.292747 | controller |
2026-01-29 20:14:54.292759 | controller | Failed to import test module: cyborg_tempest_plugin.tests.api.test_deployable_negative
2026-01-29 20:14:54.292770 | controller | Traceback (most recent call last):
2026-01-29 20:14:54.292781 | controller | File "/usr/lib/python3.12/unittest/loader.py", line 394, in _find_test_path
2026-01-29 20:14:54.292795 | controller | module = self._get_module_from_name(name)
2026-01-29 20:14:54.292808 | controller | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
2026-01-29 20:14:54.292820 | controller | File "/usr/lib/python3.12/unittest/loader.py", line 337, in _get_module_from_name
2026-01-29 20:14:54.292855 | controller | __import__(name)
2026-01-29 20:14:54.292867 | controller | File "/opt/stack/tempest/.tox/tempest/lib/python3.12/site-packages/cyborg_tempest_plugin/tests/api/test_deployable_negative.py", line 23, in <module>
2026-01-29 20:14:54.292876 | controller | class DeployableNegativeTest(base.BaseAPITest):
2026-01-29 20:14:54.292885 | controller | File "/opt/stack/tempest/.tox/tempest/lib/python3.12/site-packages/cyborg_tempest_plugin/tests/api/test_deployable_negative.py", line 31, in DeployableNegativeTest
2026-01-29 20:14:54.292895 | controller | @test.attr(type=['negative', 'gate'])
2026-01-29 20:14:54.292903 | controller | ^^^^^^^^^
2026-01-29 20:14:54.292912 | controller | AttributeError: module 'tempest.test' has no attribute 'attr'
```

By looking at the job definition of the job in cyborg-tempest-plugin https://github.com/openstack/cyborg-tempest-plugin/blob/c97c9abb569bb2b833941d022f41913ad8c03e7d/.zuul.yaml#L159
```

- job:
    name: cyborg-tempest-ipv6-only
    parent: devstack-tempest-ipv6
    description: |
      Cyborg devstack tempest tests job for IPv6-only deployment
    voting: false
    timeout: 7800
    required-projects: *base_required_projects
    vars: *base_vars
    irrelevant-files: *base_irrelevant_files
```
By taking a look at required-projects: *base_required_projects yaml anchor https://github.com/openstack/cyborg-tempest-plugin/blob/c97c9abb569bb2b833941d022f41913ad8c03e7d/.zuul.yaml#L28
```
    required-projects: &base_required_projects
      - openstack/cyborg
      - openstack/python-cyborgclient
      - openstack/tempest
      - name: openstack/cyborg-tempest-plugin
        override-checkout: 1.4.0
```
It uses a pinned version of cyborg-tempest-plugin and tempest.test has dropped support of attr long time back. Hence the pin needs to be removed in order to fix it.