Uploading folders doesn't work

### Contribution guidelines

- [X] I've read the [code of conduct](https://github.com/xwiki-labs/cryptpad/blob/main/CODE_OF_CONDUCT.md) and wholeheartedly agree

### I've found a bug and checked that ...

- [X] I understand that not following the below instructions will result in immediate closure and/or deletion of my issue.
- [X] I have understood that this bug report is dedicated for bugs, and not for support-related inquiries.
- [X] I have understood that answers are voluntary and community-driven, and not commercial support.
- [X] I have verified that my issue has not been already answered in the past. I've read the [Common issues documentation section](https://docs.cryptpad.org/en/FAQ.html#common-issues) and I also checked [previous issues](https://github.com/xwiki-labs/cryptpad/issues).

### Description

Uploading folders doesn't work on iOS.

### Steps to reproduce

1. Open the mobile-only menu 🔽 on the top right
2. Tap "Upload folder"
3. Try to select a folder on your device, tap on it
4. The folder open, you can't select it


### Expected behavior

There should be a way to upload folders, as on the other platforms.

### System information

| Question | Answer |
| --- | --- |
| Operating system and version | iOS v16.3 (20D47) |
| Web browser and version| Safari and Firefox v109.0 (25841) |
| Extensions installed | none |
| Browser tweaks | none |
| CryptPad version | 5.2.1 |