Room and client are marked "unread" when notifications are set to "mentions & keywords"

### Steps to reproduce

1. Join a very busy room like #thunderbird:mozilla.org
2. Set notifications to only care about mentions & keywords
3. Not just the room gets marked as unread but also the client titel has a permanent * indicating an unread message and there's a coloured circle on the tray icon
4. Setting low priority also doesn't help. The only way is to turn off notifications completely, rendering it impossible to know if you've been mentioned.

### Outcome

#### What did you expect?
That "mentions & keywords" would mean that at least the client isn't marked as unread when someone says something in a room I only want to be notified about when I'm mentioned.
#### What happened instead?
Either I'm always made aware of the fact this room is active or never, using the * in the title and the circle on the tray icon.

### Operating system

Ubuntu 18.04

### Application version

Element version: 1.11.55 Crypto version: Olm 3.2.15

### How did you install the app?

sudo flatpak install im.riot.Riot

### Homeserver

1.99.0+bullseye1

### Will you send logs?

Yes