refactor(clippy): Reduce some Clippy warnings #2921

Job	Run time
Check Style	10s
semver	18s
Verify hyper.h is up to date	21s
minimal-versions	28s
Test C API (FFI)	35s
Test cargo-c support (FFI)	27s
features	1m 54s
Test with Miri	2m 44s
Check MSRV	40s
Test stable on ubuntu-latest	58s
udeps	27s
Test stable on windows-latest	57s
Test stable on macOS-latest	1m 12s
Test beta on ubuntu-latest	1m 7s
Test beta on windows-latest	58s
Test beta on macOS-latest	58s
Test nightly on ubuntu-latest	56s
Test nightly on windows-latest	58s
Test nightly on macOS-latest	58s
Build docs	0s
Check exposed types	0s
CI is green	0s
	17m 6s

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