There is a new pull request by ProjectMoon against master on the void-packages repository

https://github.com/ProjectMoon/void-packages riot-desktop-1.6.8
https://github.com/void-linux/void-packages/pull/23388

riot-desktop: update to 1.6.8.
New package upgrades to Electron 9, which should restore built-in support for most system tray icons.

A patch file from https://github.com/void-linux/void-packages/pull/23388.patch is attached