Add dev-qt from an older version of the gentoo repo

Qt5 has been removed, we restore it since we still use it.

dev-qt/qtbase/files/qtbase-6.8.2-QTBUG-133500.patch

@@ -0,0 +1,58 @@
+Combined backport of [1][2][3] from upcoming Qt 6.8.3 for [4][5][6].
+
+[1] https://github.com/qt/qtbase/commit/12d4bf1ab52748cb84894f50d437064b439e0b7d
+[2] https://github.com/qt/qtbase/commit/2ef615228bba9a8eb282437bfb7472f925610e89
+[3] https://github.com/qt/qtbase/commit/a43c7e58046604796aa69974ea1c5d3e2648c755
+[4] https://bugreports.qt.io/browse/QTBUG-133206
+[5] https://bugreports.qt.io/browse/QTBUG-133500
+[6] https://bugs.kde.org/show_bug.cgi?id=499537
+--- a/src/corelib/global/qlibraryinfo.cpp
++++ b/src/corelib/global/qlibraryinfo.cpp
+@@ -7,4 +7,5 @@
+ #include "qfile.h"
+ #if QT_CONFIG(settings)
++#include "qresource.h"
+ #include "qsettings.h"
+ #endif
+@@ -104,5 +105,5 @@
+ 
+     QString qtconfig = QStringLiteral(":/qt/etc/qt.conf");
+-    if (QFile::exists(qtconfig))
++    if (QResource(qtconfig, QLocale::c()).isValid())
+         return std::make_unique<QSettings>(qtconfig, QSettings::IniFormat);
+ #ifdef Q_OS_DARWIN
+--- a/src/corelib/text/qlocale.cpp
++++ b/src/corelib/text/qlocale.cpp
+@@ -1113,8 +1113,11 @@
+ 
+ QLocale::QLocale()
+-    : d(*defaultLocalePrivate)
++    : d(c_private())
+ {
+-    // Make sure system data is up to date:
+-    systemData();
++    if (!defaultLocalePrivate.isDestroyed()) {
++        // Make sure system data is up to date:
++        systemData();
++        d = *defaultLocalePrivate;
++    }
+ }
+ 
+--- a/src/corelib/text/qlocale_unix.cpp
++++ b/src/corelib/text/qlocale_unix.cpp
+@@ -128,4 +128,6 @@
+ {
+     QSystemLocaleData *d = qSystemLocaleData();
++    if (!d)
++        return QVariant();
+ 
+     if (type == LocaleChanged) {
+--- a/src/corelib/text/qlocale_win.cpp
++++ b/src/corelib/text/qlocale_win.cpp
+@@ -829,4 +829,6 @@
+ {
+     QSystemLocalePrivate *d = systemLocalePrivate();
++    if (!d)
++        return QVariant();
+     switch(type) {
+     case DecimalPoint: