Add worker service account for LocalKubernetesExecutor

[Chen-Oliver]

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HTTP response body: {"kind":"Status","apiVersion":"v1","metadata":{},"status":"Failure","message":"pods \"extract-57f0f8f6590045d59eb2d36ce2bacb53\" is forbidden: error looking up service account airflow/airflow-worker: serviceaccount \"airflow-worker\" not found","reason":"Forbidden","details":{"name":"extract-57f0f8f6590045d59eb2d36ce2bacb53","kind":"pods"},"code":403}
WARNING - ApiException when attempting to run task, re-queueing. Reason: 'Forbidden'. Message: pods "extract-57f0f8f6590045d59eb2d36ce2bacb53" is forbidden: error looking up service account airflow/airflow-worker: serviceaccount "airflow-worker" not found

When using the KubernetesExecutor as part of LocalKubernetesExecutor, it will fail due to a missing worker service account. This PR fixes that issue. Have tested this fix on the latest helm chart version.

^ Add meaningful description above

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[jedcunningham]

Thanks @Chen-Oliver. Can you add some test coverage for the various executor options here as well?

[Chen-Oliver]

Thanks @Chen-Oliver. Can you add some test coverage for the various executor options here as well?

I've added a simple test, hopefully it is sufficient :)

[potiuk]

rebased to account for doc failure fixed in main

[boring-cyborg]

Awesome work, congrats on your first merged pull request!

[jedcunningham]

Thanks @Chen-Oliver! Congrats on your first commit 🎉