MacOS Nixpkgs CI fails on MacOS 11.6

[aherrmann]

Describe the bug CI fails on macOS 11.6 (macos-latest at the time of writing).

Setup.hs: Missing dependency on a foreign library:
* Missing (or bad) C library: z

This failure seems directly related to the OS version: Rerunning a previously passing CI run on master fails with the later macOS version.

To Reproduce Run the macOS nixpkgs CI pipeline on macOS 11.6.

Expected behavior CI should pass

Environment

• OS name + version: macOS 11.6
• Bazel version: 4.1.0
• Version of the rules: master (a70f161b891c610b66cfa740fe27adaeb07333de)

Additional context https://github.com/tweag/rules_haskell/pull/1606#issuecomment-942285370