KDE: Update KDE Plasma Desktop to 5.23.1

Plasma 5.23 was released in October 2021 with many feature refinements
and new modules to complete the desktop experience.

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

• Discover: Flatpak, do not crash when a source is disabled.
• KScreenLocker: Fix sleep and hibernate actions.
• Plasma Desktop: Fix “clear emoji history” action.

View full changelog:
https://kde.org/announcements/changelogs/plasma/5/5.23.0-5.23.1