Spotlight search can mislabel rooms with parted mxids

### Steps to reproduce

* I hit cmd-K, and searched for Rick with spotlight on.
* One of the rooms returned was called "Rick" with rick's avatar, but was labelled with mxid `@random:example.com`
* This is scary as hell as it looks like `@random:example.com` is spoofing Rick

### Outcome

What happened is that i had a three-way private room with Rick and Random a few years ago. Random subsequently left, leaving it as me & Rick. The room has no name, so its name is shown as 'Rick'. However, as Random had left, his mxid should not be shown by spotlight.

### Operating system

_No response_

### Application version

Nightly

### How did you install the app?

_No response_

### Homeserver

_No response_

### Will you send logs?

No