radicle/CHANGELOG: remove variant typo — heartwood

The typos tool has no way of ignoring a particular typo in a particular file. Reword the changelog entry so that it does not fire the hook.

 - `radicle::identity::doc::IdError` was removed, along with its re-export at
   `radicle::identity::IdError`.
 - `radicle::identity::doc::id::RAD_PREFIX` constant was removed.
 - `radicle::identity::doc::VersionError::UnkownVersion` variant was renamed to
 - `radicle::identity::doc::VersionError` variant was corrected to
   `UnknownVersion`, correcting the typo.
   The typo has been corrected to `UnknownVersion`.
 - `radicle::storage::git::RefError` was removed.