chore(clippy): fix clippy issues for rustc 1.66.0

[dan-da]

The latest rustc 1.66.0 toolchain issues a bunch of clippy warnings/errors, which CI is unhappy with.

This fixes that so clippy is happy, eg:

$ cd Kindelia

$ cargo --version
cargo 1.66.0 (d65d197ad 2022-11-15)

$ cargo clippy --all-targets --all-features
    Finished dev [unoptimized + debuginfo] target(s) in 0.28s

edit: rustfmt (cargo fmt) should also be run over the entire repo and I'm happy to make a PR for that, but there are a bunch of PRs pending, and I think its best to wait until most of those have been merged to avoid some unnecessary conflicts.