sha2: enable asm for hardware SHA-256 with runtime detection - #78

Node.js 20 is deprecated. The following actions target Node.js 20 but are being forced to run on Node.js 24: errata-ai/vale-action@91ac403e8d26f5aa1b3feaa86ca63065936a85b6. For more information see: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/