www/node20: Update to 20.20.0
Changes: https://github.com/nodejs/node/releases
https://github.com/nodejs/node/blob/main/doc/changelogs/CHANGELOG_V20.md
Security: CVE-2025-55130, CVE-2025-55131, CVE-2025-55132, CVE-2025-59465, CVE-2025-59466, CVE-2026-21637