When running WiredTiger with tiered storage we pass the field tiered_storage.auth_token which will contains details for accessing the backing cloud storage.
However, if a parsing error occurs on the provided configuration string WiredTiger will print the string including the token. For evergreen failures this results in the token being saved to our evergreen logs unintentionally.

Ideally this is handled at the evergreen layer, and EVG-19195 exists to track this, but current scheduling means this won't be delivered in the near future. As an interim measure we should redact this key in WiredTiger as part of __config_err.

As __config_err uses string offset to report the problem character in the config string, we'll need to maintain the existing length of the auth_token field but replace its contents with generic text. We currently use REDACTED in our utility tool to suppress keys and values, but don't retain the key/value length when dumping.

A review of api_data.py doesn't show any other fields that will require this redaction and long term we're expecting this behavior at the Evergreen layer. As such we can limit this change to just auth_token.