azdev test failing with LROPoller Error

Running `azdev test` is failing on our private preview extension with the following error, please help resolve this
```
self =

def tearDown(self):
os.environ = self.original_env
# Autorest.Python 2.x
assert not [t for t in threading.enumerate() if t.name.startswith("AzureOperationPoller")], \
"You need to call 'result' or 'wait' on all AzureOperationPoller you have created"
# Autorest.Python 3.x
> assert not [t for t in threading.enumerate() if t.name.startswith("LROPoller")], \
"You need to call 'result' or 'wait' on all LROPoller you have created"
E AssertionError: You need to call 'result' or 'wait' on all LROPoller you have created

env\lib\site-packages\azure_devtools\scenario_tests\base.py:154: AssertionError
------------------------------------------------------------------------------------------------------------------ Captured stderr call -------------------------------------------------------------------------------------------------------------------
WARNING: Command group 'k8s-extension' is in preview and under development. Reference and support levels: https://aka.ms/CLI_refstatus
Ignoring name, release-namespace and scope parameters since microsoft.azuremonitor.containers only supports cluster scope and single instance of this extension
--------------------------------------------------------------------- generated xml file: C:\Users\joinnis\.azdev\env_config\Users\joinnis\github\narayan-cli-pr\env\test_results.xml ---------------------------------------------------------------------
================================================================================================================= short test summary info =================================================================================================================
FAILED src\k8s-extension\azext_k8s_extension\tests\latest\test_k8s_extension_scenario.py::K8sExtensionScenarioTest::test_k8s_extension - AssertionError: You need to call 'result' or 'wait' on all LROPoller you have created
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! stopping after 1 failures !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! xdist.dsession.Interrupted: stopping after 1 failures !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
=================================================================================================================== 1 failed in 11.24s ====================================================================================================================
```

`azdev test` で失敗を再現し、`src/k8s-extension/azext_k8s_extension/tests/latest/test_k8s_extension_scenario.py::K8sExtensionScenarioTest::test_k8s_extension` から始めます。`azure_devtools/scenario_tests/base.py` の teardown assertion を読み、どの LROPoller がアクティブなままなのかを特定します。このシナリオテストが assertion failure なしで完了すれば完了です。

索引モデルが issue の本文から書いたものです。