dev-qt/qtbase: backport fix for kwin x11 excessive cpu usage

Patch is fairly simple and should be safe, tentatively doing
straight-to-stable for less hassle.

Signed-off-by: Ionen Wolkens <ionen@gentoo.org>

dev-qt/qtbase/files/qtbase-6.9.1-kwin-x11-cpu-usage.patch

@@ -0,0 +1,14 @@
+https://bugs.kde.org/show_bug.cgi?id=489230
+https://bugs.kde.org/show_bug.cgi?id=484323
+https://codereview.qt-project.org/c/qt/qtbase/+/663811
+--- a/src/plugins/platforms/xcb/qxcbscreen.cpp
++++ b/src/plugins/platforms/xcb/qxcbscreen.cpp
+@@ -501,3 +501,2 @@
+     if (connection->isAtLeastXRandR12()) {
+-        xcb_randr_select_input(xcb_connection(), screen()->root, true);
+         auto crtc = Q_XCB_REPLY_UNCHECKED(xcb_randr_get_crtc_info, xcb_connection(),
+@@ -607,4 +606,2 @@
+ 
+-    xcb_randr_select_input(xcb_connection(), screen()->root, true);
+-
+     m_monitor = monitorInfo;

dev-qt/qtbase/qtbase-6.9.1-r3.ebuild

@@ -182,6 +182,7 @@ PATCHES=(
 	"${FILESDIR}"/${PN}-6.9.0-no-direct-extern-access.patch
 	"${FILESDIR}"/${PN}-6.9.1-QTBUG-137755.patch
 	"${FILESDIR}"/${PN}-6.9.1-CVE-2025-5992.patch
+	"${FILESDIR}"/${PN}-6.9.1-kwin-x11-cpu-usage.patch
 )
 
 src_prepare() {