Upgrade cargo dependencies: `buf_redux`, `multipart`, `nom`

`cargo check` output:

```s
warning: the following packages contain code that will be rejected by a future version of Rust: buf_redux v0.8.4, multipart v0.18.0, nom v5.1.2
note: to see what the problems were, use the option `--future-incompat-report`, or run `cargo report future-incompatibilities --id 14`
```