Upgrade zlib-rs to 0.3.0 to get multiple bugfixes

[Shnatsel]

Fixes at least these correctness issues:

trifectatechfoundation/zlib-rs#165
trifectatechfoundation/zlib-rs#169
trifectatechfoundation/zlib-rs#172

And possibly others.

[Byron]

Thanks a lot!

Could you also add GitHub links (essentially the body of the PR) into the commit?

[Shnatsel]

I believe the merge commit would have PR description as the commit message anyway. But sure, done.

[Byron]

Thanks a lot, this should do it.

If merge-commits would come up in code-lens or similar tools, that should be enough as well. I am not sure they do though.

Would you consider applying the suggestion? Once again I am too afraid to do it myself as it might prevent merging 😅.

[folkertdev]

also if you actually want to use this, it makes sense to bump the flate2 version too, see e.g. https://github.com/rust-lang/flate2-rs/pull/415/files

[Shnatsel]

I assume @Byron will bump it as part of the usual release process. If not, I'm happy to increment that number, sure.

[Byron]

Actually, changing the version number will make a release more straightforward. It's a bit like being a genie, limitless power, but impossible to use for yourself :D.

[Shnatsel]

Version bumped

[Byron]

Thanks a lot!