Port away from QWindow::requestActivate()

When opining the top panel (swipe down), the warning message is apared in journald

STEPS TO REPRODUCE

open the journal on your Plasma Mobile phone (journalctl -f)
open the top panel (swipe down)

OBSERVED RESULT Jun 06 11:11:47 plasma-mobile plasmashell[4464]: qt.qpa.wayland: Wayland does not support QWindow::requestActivate()

EXPECTED RESULT no warning message

SOFTWARE/OS VERSIONS Linux/KDE Plasma: Linux plasma-mobile 5.12.9-1-MANJARO-ARM #1 (closed) SMP Thu Jun 3 10:11:08 UTC 2021 aarch64 GNU/Linux KDE Plasma Version: 5.21.5 KDE Frameworks Version: 5.82.0 Qt Version: 5.15.2