chore: clippy pendantic fixes

[Nicceboy]

Fixes some clear clippy pedantic suggestions but not all of them.

[Nicceboy]

Also allows following lints:

#![allow(
    clippy::missing_errors_doc,
    clippy::float_cmp,
    clippy::no_effect_underscore_binding,
    clippy::items_after_statements
)]

Should we start collecting some lints in Cargo.toml for workspace level?

[XAMPPRocky]

Thank you for your PR! sorry for the delay on this one, would be able to re-open it / resolve conflicts?

[Nicceboy]

I made rebase but there seems to be other issues. Is rust-toolchain file still relevant or can we remove it? It seems to now override in general everything.

[Nicceboy]

Especially APER seems to have some dead code in tests with commented code. Uncommented code fails tests, not sure if those should be looked into. For now, dead code is allowed, which failed the CI.

[XAMPPRocky]

Thank you for your PR!