[AIP-94] Mark dags list-import-errors as migrated to airflowctl

[yuseok89]

related: #68402

Routes airflow dags list-import-errors through the API server and deprecates it for airflowctl dags list-import-errors. --local still reads local Dag bundles.

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Was generative AI tooling used to co-author this PR?

• Yes (please specify the tool below)
  • Opus 4.8

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[yuseok89]

@bugraoz93
Following the converted direction, I've reworked this PR to be marker-only.
I dropped the earlier change that routed the command through the API server.
Does this match what you had in mind?
If so, I'd like to quickly roll the same change out to the other open PRs.

[bugraoz93]

@bugraoz93 Following the converted direction, I've reworked this PR to be marker-only. I dropped the earlier change that routed the command through the API server. Does this match what you had in mind? If so, I'd like to quickly roll the same change out to the other open PRs.

Yes, thanks a lot!