KDE: Update Plasma Desktop to 5.27.8

KDE Plasma 5.27.8, Bugfix Release for September

Tuesday, 12 September 2023. Today KDE releases a bugfix update to KDE
Plasma 5, versioned 5.27.8.

Plasma 5.27 was released in February 2023 with many feature refinements
and new modules to complete the desktop experience.

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

 * KRunner: make debut on X11 faster.
 * Powerdevil: don't automatically suspend by default if running in a
   virtual machine.
 * System Settings: Remove soft hyphens in keywords used for searching.

Announcement:	https://kde.org/announcements/plasma/5/5.27.8/
Changelog:	https://kde.org/announcements/changelogs/plasma/5/5.27.7-5.27.8/