fix message channels stuck in ONGOING (#17492)

`markAsMessagesListFetchOngoing()` was missing `syncStageStartedAt`
causing stuck channels to be never recovered.

Regression was caused by commit
[68a9ef57f0](https://github.com/twentyhq/twenty/commit/68a9ef57f0)

packages/twenty-server/src/modules/messaging/common/services/message-channel-sync-status.service.ts

@@ -199,6 +199,7 @@ export class MessageChannelSyncStatusService {
       await messageChannelRepository.update(messageChannelIds, {
         syncStage: MessageChannelSyncStage.MESSAGE_LIST_FETCH_ONGOING,
         syncStatus: MessageChannelSyncStatus.ONGOING,
+        syncStageStartedAt: new Date().toISOString(),
       });
     }, authContext);
   }
@@ -277,6 +278,7 @@ export class MessageChannelSyncStatusService {
 
       await messageChannelRepository.update(messageChannelIds, {
         syncStage: MessageChannelSyncStage.MESSAGES_IMPORT_ONGOING,
+        syncStatus: MessageChannelSyncStatus.ONGOING,
         syncStageStartedAt: new Date().toISOString(),
       });
     }, authContext);