x11/plasma5-plasma: Update KDE Plasma Desktop to 5.22.4

Plasma 5.22 was released in June 2021 with many feature refinements and
new modules to complete the desktop experience.

This release adds three weeks' worth of new translations and fixes from
KDE's contributors. The bugfixes are typically small but important and
include:

• Discover: Address the keyboard shortcut tooltip.
• Sort Unsplash POTD image categories alphabetically.
• Info Center: Unbreak about CPU value when solid is missing a product string.

[1] https://kde.org/announcements/plasma/5/5.22.4/