KDE: Update Plasma to 6.4.0

Announcements:

https://kde.org/announcements/plasma/6/6.4.0/
https://kde.org/announcements/plasma/6/6.3.91/
https://kde.org/announcements/plasma/6/6.3.90/

New ports added:

x11-themes/plasma6-aurorae: Aurorae window decoration
x11-wm/plasma6-kwin-x11: KWin for X11

Removed ports:

sysutils/plasma6-drkonqi: requires Systemd

kde.mk:

• Add aurorae and kwin-x11 to the list of Plasma components
• Remove drkonqi

x11/plasma6-kscreen:

• Add missing build dep on wayland-protocols. pkgconfig is required to find wayland-protocols data location

sysutils/plasma6-polkit-kde-agent-1:

• Refresh USE_KDE

sysutils/plasma6-plasma-systemmonitor:

• Add runtime deps on ksystemstats

x11-wm/plasma6-kwin*:

• Depend on aurorae and switch breeze to runtime dependence

x11/plasma6-plasma-workspace:

• Depend on kwin-x11
• Refresh USE_QT
• Add GTK option for better integration of GTK apps

x11-wm/plasma6-kwin:

• update COMMENT