fix(deps): update astro monorepo

Author: renovate[bot]

package.json

@@ -30,13 +30,13 @@
   },
   "dependencies": {
     "@astrojs/check": "^0.9.6",
-    "@astrojs/mdx": "^4.3.13",
+    "@astrojs/mdx": "^5.0.0",
     "@astrojs/rss": "^4.0.15",
     "@astrojs/sitemap": "^3.7.0",
     "@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",