Fix new Rust 1.83 clippy lints

[MarijnS95]

Clippy is once again detecting more noise and simplifications in codebases 🎉

[MarijnS95]

Besides fixing plain errors, we should also look into warnings like what's fixed on the cc side with rust-lang/cc-rs#1256. cc-rs is going to pass --target with a version making our hardcoded version-min "obsolete":

xbuild/xbuild/src/cargo/mod.rs

Lines 362 to 364 in ffe3e34

	self.add_cflag(&format!("-miphoneos-version-min={}", minimum_version));
	self.add_link_arg("--target=arm64-apple-ios");
	self.add_link_arg(&format!("-miphoneos-version-min={}", minimum_version));

Resulting in warnings like:

warning: [email protected]: clang: warning: overriding '-miphoneos-version-min=14.0' option with '--target=arm64-apple-ios17.5' [-Woverriding-t-option]