Apache Airflow: Bulk JSON Variables bypass should_hide_value_for_key - redact() called without the key

The Bulk Variables API in Apache Airflow called the redactor without passing the variable's key, so the key-based `should_hide_value_for_key` check (which triggers on secret-suffixed key names like `*_password` / `*_token` / `*_secret`) could not fire for JSON-decodable variable values. An authenticated UI/API user with bulk Variable read permission could retrieve plaintext values from JSON variables whose key would otherwise trigger redaction. Affects deployments that store sensitive values in JSON-typed Airflow Variables under secret-suffixed key names. Users are advised to upgrade to `apache-airflow` 3.3.0 or later (the fix landed on `main` after 3.2.2; no 3.2.x backport).