Update dependency @astrojs/svelte to v6

Author: renovate[bot]

package.json

@@ -18,7 +18,7 @@
     "@astrojs/prefetch": "^0.4.0",
     "@astrojs/rss": "^4.0.0",
     "@astrojs/sitemap": "^3.0.0",
-    "@astrojs/svelte": "^5.0.0",
+    "@astrojs/svelte": "^6.0.0",
     "@astrojs/tailwind": "^5.0.0",
     "date-fns": "^3.0.0",
     "svelte": "^4.0.0",