Bump coverlet.collector and 4 others - #75

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, tj-actions/changed-files@531f5f7d163941f0c1c04e0ff4d8bb243ac4366f. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/