Serializer redesign doc - #289

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v4, alandefreitas/cpp-actions/b2-workflow@v1.9.3, alandefreitas/cpp-actions/boost-clone@v1.9.3, alandefreitas/cpp-actions/cmake-workflow@v1.9.3, alandefreitas/cpp-actions/package-install@v1.9.3, alandefreitas/cpp-actions/setup-cpp@v1.9.3. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/