Fix a few lints introducedin Rust 1.77 (#348) #871

Job	Run time
test (ubuntu-latest, stable)	1m 30s
test (ubuntu-latest, beta)	1m 29s
test (windows-latest, stable)	3m 26s
linting (stable)	53s
linting (beta)	56s
test (windows-latest, beta)	3m 10s
bindings-windows (x86_64-pc-windows-msvc, true)	8m 34s
bindings-macos (x86_64-apple-darwin)	8m 4s
bindings-windows (i686-pc-windows-msvc, false)	4m 53s
documentation	8m 17s
features (--no-default-features)	1m 55s
features (--no-default-features --features serialization)	2m 1s
features (--no-default-features --features serial)	2m 3s
bindings-linux (x86_64-unknown-linux-gnu)	2m 32s
features (--no-default-features --features tls)	2m 2s
conformance	11m 20s
bindings-linux (i686-unknown-linux-gnu)	2m 39s
bindings-linux (x86_64-unknown-linux-musl)	2m 41s
bindings-linux (arm-unknown-linux-gnueabihf)	2m 49s
bindings-linux (arm-unknown-linux-musleabihf)	2m 46s
bindings-linux (aarch64-unknown-linux-gnu)	2m 41s
guide	1m 14s
bindings-linux (aarch64-unknown-linux-musl)	2m 53s
bindings-linux (armv7-unknown-linux-gnueabihf)	2m 45s
bindings-linux (arm-unknown-linux-gnueabi)	2m 46s
packaging	3m 47s
release	0s
	1h 30m 6s

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