fix(deps): update dependency astro to v6

Author: renovate[bot]

package.json

@@ -36,7 +36,7 @@
     "@fontsource/fira-mono": "^5.2.7",
     "@fontsource/pt-sans": "^5.2.8",
     "@nanostores/i18n": "^1.2.2",
-    "astro": "^5.17.1",
+    "astro": "^6.0.0",
     "astro-loader-i18n": "^0.10.11",
     "astro-nanostores-i18n": "^0.4.0",
     "embla-carousel": "^8.6.0",