Document what building droidsight needs, and attest the release archives - #22

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: ilammy/setup-nasm@72793074d3c8cdda771dba85f6deafe00623038b. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/