be explicit about a type #474

Job	Run time
Clippy	15s
cargo-c dynamic library	25s
Build and test (stable, ubuntu-latest, x86_64-unknown-linux-gnu)	37s
Clippy (--no-default-features --features="c-allocator")	15s
QEMU build & test (stable, ubuntu-latest, s390x-unknown-linux-gnu, s390x-linux-gnu-gcc, qemu-s390...	39s
Build and test (msrv, ubuntu-latest, x86_64-unknown-linux-gnu)	35s
Clippy (--no-default-features --features="std,rust-allocator")	21s
QEMU build & test (stable, ubuntu-latest, i686-unknown-linux-gnu, i686-linux-gnu-gcc)	21s
Build and test (beta, ubuntu-latest, x86_64-unknown-linux-gnu)	47s
Smoke-test fuzzing targets (ubuntu-20.04, default)	1m 44s
Build and test (stable, macos-latest, x86_64-apple-darwin)	1m 7s
Smoke-test fuzzing targets (ubuntu-20.04, c-allocator)	1m 32s
Build and test (stable, macos-14, aarch64-apple-darwin)	46s
vanilla dynamic library	19s
Miri	1m 30s
Smoke-test fuzzing targets (ubuntu-20.04, rust-allocator)	1m 34s
Build and test (stable-x86_64-gnu, windows-2022, x86_64-pc-windows-gnu)	1m 33s
Smoke-test fuzzing targets (macos-14)	1m 36s
run bzip2-rs test suite (x86_64-unknown-linux-gnu)	28s
wasm32	30s
	16m 54s

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