Fix clippy warnings

[krant]

Make cargo clippy happy

[lukipuki]

I checked and the last CI run of cargo clippy was successful, did you encounter any errors?

[lukipuki]

I'm not entirely on-board with this clippy rule but let's accept it 🙂

[krant]

My guess is that recent Rust update has introduced them - my local cargo clippy was erroring. I have no opinion regarding CI should catch those when Rust updates - pinned compiler version is good for reproducibility, so both approaches have their advantages.

[lukipuki]

I figured it out, it's a new rule in 1.88 that came out last week. Trying with cargo +1.87.0 clippy doesn't produce any warning.

[lukipuki]

If we want to make developers' lives easier, we can provide a rust-toolchain.toml file which would pin the local Rust version and it would prevent similar situations in the future.

[krant]

pin the local Rust version

I'd avoid introducing rust-toolchain.toml if the only driver for that is clippy. I hope this directive will help us to mitigate future version-related clippy hiccups.