Fix Kubernetes worker service account values

[paulkagiri]

Fixes #66579.

When workers.kubernetes.serviceAccount.create is explicitly set to false, the pod template should still use the Kubernetes worker service account name from workers.kubernetes.serviceAccount.name instead of falling back to the deprecated workers.serviceAccount values. For a pure KubernetesExecutor deployment, the legacy worker ServiceAccount should also not be rendered in that explicit Kubernetes service account path.

This keeps the existing default fallback when the Kubernetes worker service account section is not explicitly configured.

Tests:

• PYTHONPATH=chart/tests python -m pytest chart/tests/helm_tests/airflow_aux/test_pod_template_file.py::TestPodTemplateFile::test_dedicated_service_account_name_when_creation_disabled chart/tests/helm_tests/airflow_core/test_worker.py::TestWorkerKubernetesServiceAccount::test_should_not_create_legacy_service_account_when_k8s_service_account_disabled -q
• PYTHONPATH=chart/tests python -m pytest chart/tests/helm_tests/airflow_aux/test_pod_template_file.py::TestPodTemplateFile::test_service_account_name_default chart/tests/helm_tests/airflow_aux/test_pod_template_file.py::TestPodTemplateFile::test_dedicated_service_account_name_default chart/tests/helm_tests/airflow_core/test_worker.py::TestWorkerKubernetesServiceAccount::test_should_create_service_account_when_enabled -q
• python -m black --check --target-version py312 chart/tests/helm_tests/airflow_aux/test_pod_template_file.py chart/tests/helm_tests/airflow_core/test_worker.py
• python -m ruff check chart/tests/helm_tests/airflow_aux/test_pod_template_file.py chart/tests/helm_tests/airflow_core/test_worker.py
• git diff --check

[boring-cyborg]

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[jscheffl]

Looks good. Some second pair of eyes for review @Miretpl or @jedcunningham ?

[Miretpl]

Static checks requires fix tho, or revert as it failes on unrelated changes

[boring-cyborg]

Awesome work, congrats on your first merged pull request! You are invited to check our Issue Tracker for additional contributions.

[github-actions]

Backport successfully created: chart/v1-2x-test

Note: As of Merging PRs targeted for Airflow 3.X
the committer who merges the PR is responsible for backporting the PRs that are bug fixes (generally speaking) to the maintenance branches.

In matter of doubt please ask in #release-management Slack channel.

Status	Branch	Result
✅	chart/v1-2x-test