skip svelte.dev deploy. this may or may not work (#9424)

* skip svelte.dev deploy. this may or may not work

* try this

---------

Co-authored-by: Rich Harris <rich.harris@vercel.com>

Author: Rich-Harris

Diff for: sites/svelte.dev/placeholder/index.html

@@ -0,0 +1 @@
+<p>see <a href="https://github.com/sveltejs/svelte/pull/9424">#9424</a></p>

Diff for: sites/svelte.dev/vercel.json

@@ -3,5 +3,6 @@
 	"github": {
 		"silent": true
 	},
-	"buildCommand": "cd ../../packages/svelte && pnpm prepublishOnly && cd ../../sites/svelte.dev && pnpm rebuild sharp && pnpm build"
+	"buildCommand": "echo \"TODO reinstate in future: cd ../../packages/svelte && pnpm prepublishOnly && cd ../../sites/svelte.dev && pnpm rebuild sharp && pnpm build\"",
+	"outputDirectory": "placeholder"
 }