fix: update action runtime from Node.js 20 to Node.js 24 (#304)

GitHub is deprecating Node.js 20 on Actions runners:
- June 2, 2026: Node.js 24 forced as default
- September 16, 2026: Node.js 20 removed

Ref: https://github.blog/changelog/2025-09-19-deprecation-of-node-20-on-github-actions-runners/
Closes #303

Author: ChristianTellefsenAttensi

action.yml

@@ -113,6 +113,6 @@ branding:
   icon: 'box'
   color: 'gray-dark'
 runs:
-  using: 'node20'
+  using: 'node24'
   main: 'dist/main.js'
   post: 'dist/post.js'