Astro 5.8 raises Node.js requirements as support for Node.js v18 ends

Astro's new update, v5.8, raises the minimum required Node.js version to 20.3.0, 22.0.0 or higher, as Node.js 18 has reached end-of-life. Support for Node.js 18.20.8 will continue temporarily to help users migrate.

All development and CI/CD environments should be upgraded to a supported Node.js version.