Desktop client breaks E2EE for mobile (iOS) client

### ⚠️ Before submitting, please verify the following: ⚠️

- [x] This is a **bug**, not a question or a configuration issue.
- [x] This issue is **not** already reported on Github (I have searched for it).
- [x] Nextcloud Server and Desktop Client are **up to date**. See [Server Maintenance and Release Schedule](https://github.com/nextcloud/server/wiki/Maintenance-and-Release-Schedule) and [Desktop Releases](https://nextcloud.com/install/#install-clients) for supported versions.
- [x] I agree to follow Nextcloud's [Code of Conduct](https://nextcloud.com/contribute/code-of-conduct/)

### Bug description

According to iOS developer @marinofaggiana in https://github.com/nextcloud/ios/issues/4074#issuecomment-4452305001, the desktop client needs to be fixed to make E2EE on iOS work again.

As no matching issue could be found, here it is as reference. Dear desktop client developers, please fix this. All iOS users will cheer for you.

### Steps to reproduce

Something in the desktop client seems to corrupt E2EE for other clients.

### Expected behavior

Don‘t break E2EE.

### Which files are affected by this bug

All E2EE files and folders

### Operating system

Windows

### Which version of the operating system you are running.

Windows 11

### Installation method

Official Windows MSI

### Nextcloud Server version

33.0.3

### Nextcloud Desktop Client version

33.0.5

### Did this occur after an update or on a clean installation?

Major version update (i.e. 4.0.0 → 33.0.0)

### Are you using the Nextcloud Server Encryption module?

No

### Are you using an external user-backend?

- [ ] Default internal user-backend
- [ ] LDAP or Active Directory
- [ ] SSO - SAML
- [ ] Other

### Nextcloud Server logs

```shell

```

### Additional info

https://github.com/nextcloud/ios/issues/4074