Discord Notifications do not respect Do Not Disturb (Sound only)

### What Happened?

We are playing a videogame in fullscreen, with Do Not Disturb activated
Despite not receiving any visual notification, we hear the "pling!" "pling!" of new notifications
probably because Discord does not use the Notifications server to send those - But Discord should not be able to interfere! And this may be perceived as a pantheon bug by users

### Steps to Reproduce

activate DnD
receive notifications on discord - from non-muted sources

### Expected Behavior

No interference notification or sound from nonfocused applications

i am not sure whether disallowing nonfocused applications from doing any sound would be a right approach here
i can imagine people with DnD on playing music while they wortk... But then that could be doing an exception to apps using MPRIS ?

So a:
-Only focused applications
-And MPRIS clients
can do sound when DnD

count this as half issue half feature request

### OS Version

8.x (Early Access)

### Session Type

Secure Session (Wayland)

### Software Version

Latest release (I have run all updates)

### Log Output

_No response_

### Hardware Info

_No response_