Update vendored zlib to 1.4 - #1558

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@11d5960a326750d5838078e36cf38b85af677262, reactivecircus/android-emulator-runner@324029e2f414c084d8b15ba075288885e74aef9c. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/