[Bug]: Nextcloud duplicated each file in an E2E encrypted folder

### ⚠️ 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've searched 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

After disabling and enabling E2EE and an hours-long sync in an attempt to solve #6919, each and every file in two e2e encrypted folders (and each subfolder) are now duplicated with a dot "." in the beginning and a random hexcode after a tilde in the end.

### Steps to reproduce

1. have the error from #6919
2. disable e2e encryption in Nextcloud Desktop
3. enable e2e encryption
4. wait until the sync ends
5. `cd` to e2e encrypted directory
6. `ls -al`

### Expected behavior

The files should be there without a duplicate.

### Which files are affected by this bug

/Auto/Parkausweis.pdf

### Operating system

Linux

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

Arch Linux 6.9.9-arch1-1

### Package

Distro package manager

### Nextcloud Server version

28.0.6.1

### Nextcloud Desktop Client version

3.13.2

### Is this bug present after an update or on a fresh install?

Fresh desktop client install

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

Encryption is Enabled

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

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

### Nextcloud Server logs

```shell
I have no access to server log, hosted environment.
```

### Additional info

The duplicate of `/Auto/Parkausweis.pdf` is `.Parkausweis.pdf_dec.~8ce0aa0`.

Size of debug archive is 14G. Please advise.