Johannes Marbach authored May 22, 2022 and Clayton Craft committed May 29, 2022

This replaces the previous `udevadm test` hack with a combination of
`udevd`, `udevadm trigger` and `udevadm settle` in order to coldplug all
available devices and make them available for use via libinput / unl0kr.

Relates to: #1411

[ci:skip-build] already built successfully in CI