chore: import upstream snapshot with attribution

extensions/ipynb/src/notebookSerializerWorker.web.ts

@@ -0,0 +1,14 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import { serializeNotebookToString } from './serializers';
+import type { NotebookData } from 'vscode';
+
+onmessage = (e) => {
+	const data = e.data as { id: string; data: NotebookData };
+	const json = serializeNotebookToString(data.data);
+	const bytes = new TextEncoder().encode(json);
+	postMessage({ id: data.id, data: bytes });
+};