Update mock.mjs

Co-authored-by: Antoine du Hamel <[email protected]>

Author: GeoffreyBooth

test/fixtures/es-module-loaders/mock.mjs

@@ -5,7 +5,7 @@ import { MessageChannel } from 'node:worker_threads';
 
 const { port1, port2 } = new MessageChannel();
 
-register(fixtures.fileURL('es-module-loaders/mock-loader.mjs'), {
+register('./mock-loader.mjs', import.meta.url, {
   data: {
     port: port2,
     mainImportURL: import.meta.url,