Screenshare audio gets quieter when I speak / Audio Attenuation?

### Steps to reproduce

1. Where are you starting? What can you see?
2. What do you click?
3. More steps…

1. Join a call together with a friend
2. Ask your friend to screenshare something with sound (no matter if it's a single tab, window or the entire desktop)
3. Try to speak while watching the stream.
4. -> You will notice a drop in audio quality with a slight delay to when you started speaking. Besides that it also gets way quieter.

### Outcome

#### What did you expect?
I expect the audio quality and volume to stay the same

#### What happened instead?
The audio quality got worse and quieter.

#### Follow up:
I don't know if this is a feature like it can be found in Discord (voice attenuation) or if this is a bug but as of right now, listening to something in a stream is outright impossible for me. There is no option to disable this behavior and if it is a bug, I have no clue where the cause lies.

### Operating system

Windows, MacOS

### Browser information

Brave 1.90.124 (Official Build) (64-bit) Chromium: 148.0.7778.179

### URL for webapp

app.cinny.in

### Will you send logs?

No

Start by reproducing the issue in the web app using a screenshare with sound, speaking while watching the stream, and recording whether the delay and volume drop occur across the reported browsers and operating systems. Trace the screenshare audio and microphone handling from the relevant call entry points; done means streamed audio quality and volume remain unchanged while speaking, or the behavior has a user-facing disable option.

Written by the indexing model from the issue text.