Set up pedantic Clippy warnings

[jbangelo]

This sets the clippy::pedantic set of lints by default to be warnings, but remember that CI will fail on any warnings. The second commit goes through and fixes most of the new warnings. There are a handful of places where some of the lints are disabled.

Disabled lints

• #[allow(clippy::many_single_char_names)] was used twice (crate::coords::llh::LLHRadians::to_ecef(), and crate::math::compile_time_sqrt()). These two functions are rather short and implement common mathematical formulas, so there aren't really super descriptive names to give the variables and doing so would make the implementation even more different than the original source.
• #![allow(clippy::cast_possible_truncation, clippy::cast_sign_loss, clippy::cast_precision_loss)] for the entire crate::time::mjd module, basically we're doing a lot of not great casting
• #![allow(clippy::cast_possible_truncation, clippy::cast_sign_loss)] for the entire crate::time::utc module, similar use of lots of not great casting

[john-michaelburke]

Decided to look up why this is not the default generally and looks like I stumbled upon another extremely controversial topic in the Rust community lol. Kind of insane they don't have a way of setting this for all functions in the cargo.toml or something

[jbangelo]

Yeah. @tzilist has suggested to start enabling the Clippy pedantic lints on more stuff. I don't think we've spent enough time to figure out if there are lints under that category that we want to blanket ignore. I think we're all happy to hear feedback if there are ones you think are just too noisy or are overly strict.

[jbangelo]

You can enable just the must_use lint with #![warn(clippy::must_use_candidate)] or I'm sure there's a way either in the Cargo.toml or the clippy.toml as well.

[john-michaelburke]

Yeah no complaints just find it bizarre you need to cover all your functions with this attribute and there is no way to set it as a default for all functions and rather it be an opt out feature.

[tzilist]

Had a little nit, but going to approve regardless as it's quite small

[tzilist]

I think we should use expect here (which will throw an error if someone comes in and fixes the lint, and thus, can be removed). You can also add reasons into both the expect and allow macros 😄

Suggested change

	#[allow(clippy::many_single_char_names)] // It's math, whatyagonnado?
	#[expect(clippy::many_single_char_names, reason = "It's math, whatyagonnado?")]

[pcrumley]

nice i didn't know this existed!