Zooming inwards doesn't retain scroll-offset

### Steps to reproduce

1. Hit Cmd-+ or equivalent a few times to increase the font size
2. Note that the timeline scrolls off the bottom, as the scroll offset isn't maintained.

### Outcome

#### What did you expect?

It's minor polish, but i'd expect the scroll offset to be retained, rather than me having to go and manually fix the scroll position after having zoomed in.

#### What happened instead?

Content scrolls off the bottom of the page.

### Operating system

macOS 12.3 on M1

### Application version

nightly

### How did you install the app?

nightly

### Homeserver

matrix.org

### Will you send logs?

No