refactor(clippy): Reduce some Clippy warnings #2922

Job	Run time
Verify hyper.h is up to date	21s
Check Style	10s
semver	17s
minimal-versions	35s
features	39s
Test C API (FFI)	38s
Test cargo-c support (FFI)	19s
Test with Miri	2m 29s
Check MSRV	33s
Test stable on ubuntu-latest	1m 20s
udeps	19s
Test stable on windows-latest	2m 29s
Test stable on macOS-latest	1m 21s
Test beta on ubuntu-latest	1m 29s
Test beta on windows-latest	2m 25s
Test beta on macOS-latest	1m 28s
Test nightly on ubuntu-latest	1m 23s
Test nightly on windows-latest	2m 21s
Test nightly on macOS-latest	1m 40s
Check exposed types	15s
Build docs	23s
CI is green	1s
	22m 55s

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