fix: set featured status to false for GitHub Copilot Dev Days blog post

Author: harrybin

src/content/blog/github-copilot-dev-days-trier-2026.mdx

@@ -3,7 +3,7 @@ author: Harald Binkle
 pubDatetime: 2026-03-19T19:50:00Z
 title: GitHub Copilot Dev Days | Trier
 postSlug: github-copilot-dev-days-trier-2026
-featured: true
+featured: false
 draft: false
 tags:
   - GitHub Copilot