chore(deps): update dependency astro to v6 [security]

Author: renovate[bot]

package.json

@@ -142,7 +142,7 @@
     "@types/node": "24.10.4",
     "@types/wallabyjs": "0.0.15",
     "asciinema-player": "3.13.5",
-    "astro": "5.16.6",
+    "astro": "6.4.6",
     "astro-broken-link-checker": "file:./vendor/astro-broken-link-checker",
     "ava": "6.4.1",
     "bupkis": "0.14.0",