refactor(processor): pass Intersect's survivor count explicitly between rounds - #1382

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/cache/save@0057852bfaa89a56745cba8c7296529d2fc39830, actions/checkout@v4, hendrikmuhs/ccache-action@5ebbd400eff9e74630f759d94ddd7b6c26299639. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/