You are presumably running a version before Sentry 10.0.0. The error you’re receiving is issued by the Sentry server for not recognizing a property introduced in this PR, where we also changed so that unknown properties will be ignored.
Theoretically, you could downgrade sentry-cli to a much older version before this attribute was introduced. However, I highly suggest that you upgrade to a more recent Sentry version, which also comes with improved symbolication of iOS crashes.