Removes airflow ui functionality

What does this MR do and why?

We won't be working on Airflow integration, thus we are removing the implemented funcionality. This feature is behind a feature flag, and was never enabled, tables should be all empty.

Database

Migrations

main: == 20230216144719 DropTableAirflowDags: migrating =============================
main: -- drop_table(:airflow_dags, {:if_exists=>true})
main:    -> 0.0141s
main: == 20230216144719 DropTableAirflowDags: migrated (0.0317s) ====================

ci: == 20230216144719 DropTableAirflowDags: migrating =============================
ci: -- drop_table(:airflow_dags, {:if_exists=>true})
ci:    -> 0.0130s
ci: == 20230216144719 DropTableAirflowDags: migrated (0.0577s) ====================

MR acceptance checklist

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• I have evaluated the MR acceptance checklist for this MR.