[fix] don't use top level await in Edge Functions (#6360)

Fixes #6345

.changeset/shiny-sloths-juggle.md

@@ -0,0 +1,6 @@
+---
+'@sveltejs/adapter-vercel': patch
+'@sveltejs/adapter-netlify': patch
+---
+
+Don't use top-level-await, as it is not supported right now

packages/adapter-netlify/src/edge.js

@@ -4,7 +4,7 @@ import { manifest, prerendered } from 'MANIFEST';
 const server = new Server(manifest);
 const prefix = `/${manifest.appDir}/`;
 
-await server.init({
+const initialized = server.init({
 	// @ts-ignore
 	env: Deno.env.toObject()
 });
@@ -14,13 +14,14 @@ await server.init({
  * @param { any } context
  * @returns { Promise<Response> }
  */
-export default function handler(request, context) {
+export default async function handler(request, context) {
 	if (is_static_file(request)) {
 		// Static files can skip the handler
 		// TODO can we serve _app/immutable files with an immutable cache header?
 		return;
 	}
 
+	await initialized;
 	return server.respond(request, {
 		platform: { context },
 		getClientAddress() {

packages/adapter-vercel/files/edge.js

@@ -2,15 +2,15 @@ import { Server } from 'SERVER';
 import { manifest } from 'MANIFEST';
 
 const server = new Server(manifest);
-
-await server.init({
+const initialized = server.init({
 	env: process.env
 });
 
 /**
  * @param {Request} request
  */
-export default (request) => {
+export default async (request) => {
+	await initialized;
 	return server.respond(request, {
 		getClientAddress() {
 			return request.headers.get('x-forwarded-for');