Update post to reflect CNV data has been released

[ahernank]

Need to update the post on https://malariagen.github.io/vobs-updates/2024/11/29/af1.1toaf1.4update.html, to avoid confusion regarding public releases & terms of use. The aim here is to communicate that CNV data is now available, which completes the expected data (type) releases. Dropping the release from the pre=True flag communicates that no further data are expected, rather than the release being made public.