Pull-down to sync broken in 2024.12.0

### Bitwarden Beta

- [X] I'm using the new native Bitwarden Beta app and I'm aware that legacy .NET app bugs should be reported in [bitwarden/mobile](https://github.com/bitwarden/mobile)

### Steps To Reproduce

Change a vault entry (or add/delete an entry) via the web UI or chrome extension. Open the iOS app and pull down to sync.

### Expected Result

Changes are reflected in the iOS app.

### Actual Result

Pulling down appears to trigger a sync, as the grey spinner appears briefly and there are no error messages, but the changes aren't reflected in the app.

### Additional Context

Some notes:

Experiencing the same behavior in the legacy iOS app.

If I log the client out and back into the vault, a sync is performed and vault changes are reflected in the client. It is only pull-to-sync that isn't working.

I am using the Vaultwarden backend (previously known as bitwarden_rs). I have logging enabled on the backend and I can see there is no request made to the backend when manually syncing in the iOS app. Compared to when I manually sync the browser extension, which shows a sync request:

```
Jul 17 10:00:34 vaultwarden vaultwarden[94606]: [2024-07-17 10:00:34.969][request][INFO] POST /identity/connect/token
Jul 17 10:00:34 vaultwarden vaultwarden[94606]: [2024-07-17 10:00:34.970][response][INFO] (login) POST /identity/connect/token => 200 OK
Jul 17 10:00:35 vaultwarden vaultwarden[94606]: [2024-07-17 10:00:35.075][request][INFO] GET /api/sync
Jul 17 10:00:35 vaultwarden vaultwarden[94606]: [2024-07-17 10:00:35.098][response][INFO] (sync) GET /api/sync? => 200 OK
```

I get nada in the logs when syncing in the iOS app.

### Build Version

2024.7.0 (1194)

### Environment Details

- Device: iPhone 12 Pro
- iOS Version: 17.5.1

### Issue Tracking Info

- [X] I understand that work is tracked outside of Github. A PR will be linked to this issue should one be opened to address it, but Bitwarden doesn't use fields like "assigned", "milestone", or "project" to track progress.

No file or test is named. Start by tracing the iOS pull-to-sync entry point and compare it with the logout/login sync path, using the reported absence of an /api/sync request as the diagnostic signal. Done means pull-to-sync requests and applies vault changes from the web UI or browser extension.

Written by the indexing model from the issue text.