Fix build of boost::iostreams zlib filter

[benmwebb]

Explicitly add zlib to the requirements so that boost::iostreams gets built with the zlib filter. This was being pulled in implicitly at one point but recently stopped working; make it explicit. Add a compile+link test to make sure the final library includes the necessary symbols. Closes #122.

This is essentially the same as PR #115 (which fixed the issue for the 1.74.x branch) but for the main branch.

Checklist

• [x] Used a personal fork of the feedstock to propose changes
• [x] Bumped the build number (if the version is unchanged)
• [ ] Reset the build number to 0 (if the version changed)
• [x] Re-rendered with the latest conda-smithy (Use the phrase code>@<space/conda-forge-admin, please rerender in a comment in this PR for automated rerendering)
• [x] Ensured the license file is being packaged.

[conda-forge-linter]

Hi! This is the friendly automated conda-forge-linting service.

I just wanted to let you know that I linted all conda-recipes in your PR (recipe) and found it was in an excellent condition.

[jakirkham]

Thanks Ben! 😄

Let's get this in. Will follow up on the Conda-Build issue separately.