Apache Airflow: Bulk Variable and Connection endpoints record secret values in the audit log in cleartext

Apache Airflow wrote Variable values and Connection `extra` contents to the audit log in cleartext when they were submitted through the bulk endpoints (`PATCH /api/v2/variables` and `PATCH /api/v2/connections`). The audit-log masking recognised only top-level request fields, and a bulk request nests its entities two levels below, so no masking was applied to them. Any authenticated user with audit-log read access -- who need not hold Variables or Connections read at all -- could recover those secrets verbatim, and the Connection `extra` copy is stored unencrypted in the log while the connection table encrypts it. The Airflow UI's *Import Variables* action posts to this endpoint, so an ordinary operator import wrote every secret in the file to the log. This is a different code path from CVE-2026-50204: that fix shipped in 3.3.0 and covers the single-entity endpoints only, so deployments that upgraded in response to that advisory remain affected and must upgrade again. Users are advised to upgrade to apache-airflow 3.3.1 or later.