[keyserver] Update type for platform in ParsedDelivery

Summary: Should have been done in D8699, after we started putting both ios and macos in the platform field but flow didn't complain so I haven't noticed it.

Test Plan: N/A

Reviewers: marcin, tomek, inka

Reviewed By: marcin

Subscribers: ashoat

Differential Revision: https://phab.comm.dev/D8705

keyserver/src/push/rescind.js

@@ -23,7 +23,7 @@ import { dbQuery, SQL } from '../database/database.js';
 import type { SQLStatementType } from '../database/types.js';
 
 type ParsedDelivery = {
-  +platform: 'ios' | 'android',
+  +platform: 'ios' | 'macos' | 'android',
   +codeVersion: ?number,
   +notificationID: string,
   +deviceTokens: $ReadOnlyArray<string>,