Items in spotlight dialog do not visually appear to be selected when navigating with up/down key in local dev environment

### Steps to reproduce

1. Run locally with `yarn start`
2. Open spotlight dialog
3. Navigate with up/down arrow key
4. Press enter to launch into room

### Outcome

#### What did you expect?
The selected item to have a grey background.

#### What happened instead?
No special background.

### Operating system

_No response_

### Browser information
Firefox

### URL for webapp

_No response_

### Application version

_No response_

### Homeserver

_No response_

### Will you send logs?
No

Run the local app with `yarn start`, open the spotlight dialog, and reproduce the missing selection background with the up/down keys in Firefox. Trace the spotlight dialog's keyboard-selection rendering and verify that the selected item shows a grey background while pressing Enter still launches the room.

Written by the indexing model from the issue text.