The setText() support was submitted upstream at
https://github.com/snowwlex/QtWaitingSpinner/pull/14
by `huxingyi <huxingyi@msn.com>`, but not merged. The
commits from that PR were merged into Calamares' copy
of the waitingspinnerwidget files. Add relevant tags
(which aren't in the PR, but Calamares does chase SPDX)