Use mapped types around account data events (#28752)

* Use mapped types around account data events

---------

Signed-off-by: Michael Telatynski <7t3chguy@gmail.com>

test/unit-tests/utils/notifications-test.ts

@@ -6,7 +6,14 @@ SPDX-License-Identifier: AGPL-3.0-only OR GPL-3.0-only
 Please see LICENSE files in the repository root for full details.
 */
 
-import { MatrixEvent, NotificationCountType, Room, MatrixClient, ReceiptType } from "matrix-js-sdk/src/matrix";
+import {
+    MatrixEvent,
+    NotificationCountType,
+    Room,
+    MatrixClient,
+    ReceiptType,
+    AccountDataEvents,
+} from "matrix-js-sdk/src/matrix";
 import { Mocked, mocked } from "jest-mock";
 
 import {
@@ -32,7 +39,7 @@ jest.mock("../../../src/settings/SettingsStore");
 describe("notifications", () => {
     let accountDataStore: Record<string, MatrixEvent> = {};
     let mockClient: Mocked<MatrixClient>;
-    let accountDataEventKey: string;
+    let accountDataEventKey: keyof AccountDataEvents;
 
     beforeEach(() => {
         jest.clearAllMocks();