Upgrade zlib-rs to 0.3.0 to get multiple bugfixes #378

Job	Run time
Minimum Rust compiler	45s
Rustfmt & Docs	15s
Test (stable)	1m 32s
Minimum Rust compiler (windows-2022)	2m 33s
Test (beta)	1m 34s
Minimum Rust compiler (macos-latest)	1m 18s
Test (nightly)	1m 22s
Minimum Rust compiler (ubuntu-latest)	1m 18s
Test (macos)	1m 24s
Test (windows)	5m 6s
Test (mingw)	1m 55s
WebAssembly (wasm32-unknown-unknown)	5s
WebAssembly (wasm32-wasi)	8s
	19m 15s

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