Export from element-desktop seems to produce corrupt attachments

### Steps to reproduce

Export chat in any room with attachments, click "include attachments"

### Outcome

#### What did you expect?

To be able to open attachments.

#### What happened instead?

All downloaded attachments (tested on images and audio messages) were corrupt and unable to open (or possibly still encrypted?).

Note that when I exported the same room in the same way from the web version it worked fine.

### Operating system

Mint 22.1

### Application version

Element version: 1.11.104 Crypto version: Rust SDK 0.11.0 (404ca47), Vodozemac 0.9.0

### How did you install the app?

From the .deb repository

### Homeserver

matrix.org

### Will you send logs?

No