The internal API request made by TranslationEditPage::getEditInfo() is using prop=info&intoken=edit to request an edit token. That was deprecated in MediaWiki 1.24 in favor of the meta=tokens module.

Ideally you'd remove the internal API call entirely in favor of calling the appropriate backend methods directly, but at least don't make internal API calls that log deprecated feature uses to the 'api-feature-usage' channel.