remove "here be dragons" warning (sveltejs#353)

* remove "here be dragons" warning

* bump site-kit

---------

Co-authored-by: Rich Harris <[email protected]>

Author: Rich-Harris

package.json

@@ -16,7 +16,7 @@
 		"@playwright/test": "^1.31.2",
 		"@sveltejs/adapter-vercel": "2.3.1",
 		"@sveltejs/kit": "^1.15.0",
-		"@sveltejs/site-kit": "^3.3.6",
+		"@sveltejs/site-kit": "^4.0.1",
 		"@types/diff": "^5.0.2",
 		"@types/marked": "^4.0.8",
 		"@types/prismjs": "^1.26.0",