docs: fix typo in `Step::Drop`
@@ -507,7 +507,8 @@ mod tests {
/// Drop partitions.
///
- /// Note that this only works for fully persisted partitions.
+ /// Note that this only works for fully persisted partitions if
+ /// the database is configured for persistence.
///
/// The partitions are by table name and partition key.
Drop(Vec<(&'static str, &'static str)>),
