Settings UI fails if one adds a non-policy policy room

### Steps to reproduce

1. Use the experimental ignores using policy lists
2. Add a policy room that has a non `m.policy` type

### Outcome

#### What did you expect?
Error modal
#### What happened instead?
Dialog suddenly broke
On the next access to the setting window, it turns out the room has silently been added to the ignore rooms list

### Operating system

*irrelevant*

### Application version

1.11.8

### How did you install the app?

dpkg/apt

### Homeserver

matrix.org

### Will you send logs?

Yes