chore(CI): Update Cargo.lock.msrv

- Reduces multi-versioned deps
- Now compatible with Rust 1.56.1

Lock file was created with:

```bash
cargo +nightly update -Z msrv-policy
cargo update --package memchr --precise 2.5.0
cargo update --package ordered-multimap --precise 0.4.0
cargo update --package tokio-util --precise 0.7.8
```

Signed-off-by: Brennan Kinney <[email protected]>