Fix Qt6 building (#4393)

src/widgets/helper/ResizingTextEdit.cpp

@@ -62,7 +62,11 @@ QString ResizingTextEdit::textUnderCursor(bool *hadSpace) const
 
     auto textUpToCursor = currentText.left(tc.selectionStart());
 
+#if QT_VERSION >= QT_VERSION_CHECK(5, 15, 0)
+    auto words = QStringView{textUpToCursor}.split(' ');
+#else
     auto words = textUpToCursor.splitRef(' ');
+#endif
     if (words.size() == 0)
     {
         return QString();

src/widgets/helper/SettingsDialogTab.cpp

@@ -54,7 +54,7 @@ void SettingsDialogTab::paintEvent(QPaintEvent *)
     QPainter painter(this);
 
     QStyleOption opt;
-    opt.init(this);
+    opt.initFrom(this);
 
     this->style()->drawPrimitive(QStyle::PE_Widget, &opt, &painter, this);