applets/taskmanager: Workaround for QTBUG-102811
When the size of ScrollView depends on its delegate items and reuseItems
is set to true, the program is prone to crash.
Although delayed binding on Layout.minimumWidth mitigates the crash,
there are still some related crash reports.
This adds a workaround for QTBUG-102811 to fix the potential crash. To
reproduce the crash, open 20 Konsole windows and 2 windows of other
program, set delayed: false in Binding on Layout.minimumWidth in the
origin code, and move mouse between the two grouped tasks in the task
manager.
Edited by Fushan Wen