1:1 calls not calling when calls are simultaneously opened by the two users

### Steps to reproduce

1. Call a user (1:1 call)
2. While the call is started, the called user starts a new 1:1 call

### Outcome

#### What did you expect?
Like Discord the two started calls should merge together
#### What happened instead?
The two calls are independent and they aren't connected (also I can't see the incoming call notifications)

### Operating system

Windows

### Browser information

Edge 127

### URL for webapp

develop.element.io/app.element.io

### Application version

0.0.1-nightly.2024072901

### Homeserver

matrix.org

### Will you send logs?

No