fix(deps): update astro to v6 (#337)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

package.json

@@ -42,7 +42,7 @@
     "@iconify-json/mdi": "1.2.3",
     "@octokit/openapi-types": "27.0.0",
     "@tailwindcss/vite": "4.2.1",
-    "astro": "5.18.0",
+    "astro": "6.0.2",
     "astro-icon": "1.1.5",
     "date-fns": "4.1.0",
     "marked": "17.0.4",