fix internal usage of global instead of globalThis (#963)

Author: dario-piotrowicz

.changeset/tidy-geese-film.md

@@ -0,0 +1,5 @@
+---
+'@cloudflare/next-on-pages': patch
+---
+
+fix internal usage of `global` instead of `globalThis` (which causes some reference errors)

packages/next-on-pages/templates/_worker.js/index.ts

@@ -44,10 +44,10 @@ const patchedDefineProperty = (
 	return originalDefineProperty(...args);
 };
 
-global.Object.defineProperty =
-	patchedDefineProperty as typeof global.Object.defineProperty;
+globalThis.Object.defineProperty =
+	patchedDefineProperty as typeof globalThis.Object.defineProperty;
 
-global.AbortController = class PatchedAbortController extends AbortController {
+globalThis.AbortController = class PatchedAbortController extends AbortController {
 	constructor() {
 		try {
 			super();