Tasks app interface is broken

### What Happened?

I had some issues previously regarding Nvidia drivers (see #276).
Since then, the Tasks app was updated and the Flatpak app now works! Sadly, the interface still has misplaced elements and the app is basically not usable:

I think the problem is faulty app data (which can't be uninstalled through a GUI). There is a way of uninstalling a Flatpak app with all of its data using `flatpak uninstall io.elementary.tasks --delete-data`, but as this data comes from the old app (previously not distributed as Flatpak due to problems with certain graphic cards), the interface remains broken.

Is there any way I could fix that?

### Steps to Reproduce

1. Open the Tasks app
2. Misplaced elements show up in the user interface

### Expected Behavior

The Tasks app should be usable, with fully functional UI.

### OS Version

6.x (Odin)

### Software Version

Latest release (I have run all updates)

### Log Output

_No response_

### Hardware Info

Running elementary OS Odin (dual-booting Windows 10)
Computer: Lenovo Legion 5
Processor: AMD Ryzen 7 4800h + integrated Radeon Graphics
Graphics card: Nvidia GTX 1660 ti Mobile (nvidia-driver-470 from the AppCenter - 470.57.02)
Memory: 16GB
Storage: 512GB SSD

Tasks app version 6.0.4 from AppCenter