feat: support linuxbrew installed zlib headers

[chenrui333]

• 👋 while building xclogparser 0.2.40 Homebrew/homebrew-core#201480 for linux, seeing some build failures searching linux headers

  /tmp/xclogparser-20241217-6857-xho898/XCLogParser-0.2.40/.build/checkouts/GzipSwift/Sources/system-zlib/include/module.modulemap:2:12: error: header '/usr/include/zlib.h' not found
  1 | module zlibLinux [system] {
  2 |     header "/usr/include/zlib.h"
    |            `- error: header '/usr/include/zlib.h' not found
  3 |     header "/usr/include/zconf.h"
  4 |     link "z"
  
  /tmp/xclogparser-20241217-6857-xho898/XCLogParser-0.2.40/.build/checkouts/GzipSwift/Sources/Gzip/Data+Gzip.swift:32:12: error: could not build C module 'zlibLinux'
   30 | 
   31 | #if os(Linux)
   32 |     import zlibLinux
      |            `- error: could not build C module 'zlibLinux'
   33 | #else
   34 |     import zlib

linuxbrew (which is homebrew for linux) actually installs the zlib headers in ${brew --prefix}, thus adding a zlibHomebrew module lookup.

I am new to this, open for better thoughts. Thanks!