We need to replicate these changes in the Python SDK for LLMO: PostHog/posthog-js#2217

The original issue: PostHog/posthog-js#2134

Allowing inline base64 encoded images to be sent as part of the PostHog event is not safe due to the maximum size of the event.

A better approach is to first upload the image via some sort of Files API, and then use its URL. For those that still want to use inline base64 encoded images, they need to be redacted from the PostHog event.