radicle/storage: Fix temporary path generation — heartwood

impl Display for RepoId will produce a rid: prefix, which contains a colon, and this trips up various filesystems. Use RepoId::canonicial instead.

             .collect();
         let path = root
             .as_ref()
             .join(format!("{rid}.{random}"))
             .join(format!("{}.{random}", rid.canonical()))
             .with_extension(Self::EXT);
         let repo = Repository::create(&path, rid, info)?;
         Ok(Self { repo, path })