Remove obsolete timestamp declaration on TimelineCard in non-bubble layouts

[luixxiul]

Steps to reproduce

1. Enable modern layout
2. Open a room
3. Enable a widget
4. Maximize the widget
5. Send a message to the room

Outcome

What did you expect?

The timestamp width should not overflow EventTile.

What happened instead?

It overflows EventTile.

Operating system

Debian

Browser information

Firefox ESR 99

URL for webapp

localhost

Application version

develop branch

Homeserver

No response

Will you send logs?

No