By default, the `std` feature is enabled, but with
disable-default-features, it can now be either no-std/no-alloc.

This did involve a breaking change with the serialization traits, to allow
no-alloc serialization.

Serialize/Deserialize traits were sealed, and most functions were hidden

Per [updated guidance][1], it is recommended to commit the Cargo.lock, even for
libraries.

[1]: https://blog.rust-lang.org/2023/08/29/committing-lockfiles.html