matrix-react-sdk's `EventIndexPanel.tsx` does not honor `desktop_builds` configuration setting

### Your use case

#### What would you like to do?

If `desktop_builds.available` is `false`, then I believe that **General** -> **Security & Privacy** -> **Message Search** (`src/components/views/settings/EventIndexPanel.tsx` from `matrix-react-sdk`) should:

- not offer a desktop app at all (since there isn't one)
- if it does offer a desktop app, it should use the information from the `desktop_builds` settings (`logo`, `url`) and `brand` instead of hardcoding Element and links to https://element.io/get-started

Relevant code is here: [`src/components/views/settings/EventIndexPanel.tsx#L215-L235`](https://github.com/matrix-org/matrix-react-sdk/blob/73360026ab7bb76bd869a1724cf49aa6ffe60558/src/components/views/settings/EventIndexPanel.tsx#L215-L235)

### Have you considered any alternatives?

_No response_

### Additional context

_No response_