site: turn off edge serving for REPL (#9136)

Our core web vitals have really taken a hit since enabling edge serving. I ran various configs against pagespeed.web.dev and the traditional serverless functions do the best. That's at least partially because I believe serverless functions default to running in us-east-1 where our supabase instance is located. Therefore try going back to Serverless for a while to see the impact.

sites/svelte.dev/src/routes/(authed)/+layout.server.js

@@ -2,9 +2,7 @@ import * as session from '$lib/db/session';
 
 /** @type {import('@sveltejs/adapter-vercel').Config} */
 export const config = {
-	// regions: ['pdx1', 'sfo1', 'cle1', 'iad1'],
-	regions: 'all',
-	runtime: 'edge'
+  runtime: 'nodejs18.x' // see https://github.com/sveltejs/svelte/pull/9136
 };
 
 export async function load({ request }) {