Upgrade CRoaring to v5.5.5 and avoid len() in x[i] - #155

Internal server error. Correlation ID: 8c29861e-a431-48ea-8dbc-35524bb2a75e

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: actions/checkout@v3, actions/setup-python@v5.6.0. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/