Pinned messages button shouldn't appear in the room header if nothing is pinned

[robintown]

Steps to reproduce

1. Enable pinned messages in labs
2. View a room with no pinned messages

Outcome

What did you expect?

Per the designs, the pinned messages button should be absent from the room header.

What happened instead?

The pinned messages button is still there.

Operating system

NixOS unstable

Browser information

Firefox 97.0.1

URL for webapp

develop.element.io

Application version

Element version: 95de708-react-76ca0362e15d-js-58756a1973f2 Olm version: 3.2.8

Homeserver

Synapse 1.52.0

Will you send logs?

No