Spoilers with mentions ping the user and leak the visual highlight color

### Steps to reproduce

1. send `/spoiler @room` or something

### Outcome

#### What did you expect?
if it's going to be blurred by spoiler tag, then it shouldn't leak

#### What happened instead?
ping and visual highlight etc

### Operating system

arch

### Application version

nightly

### How did you install the app?

aur

### Homeserver

_No response_

### Will you send logs?

No