Include only needed headers instead of QtConcurrent module header
While <QtConcurrentRun>
is not mentioned in the docs (QTBUG-114663), other
places in KIO and further KF modules have been using the <QtConcurrentRun>
include all the time, so doing it here is just aligning to those
expectations.
NO_CHANGELOG
Edited by Friedrich W. H. Kossebau