Fix dangling references, found by GCC 13

Lifetime extension via const-ref only applies to functions that return
by value. For those that already return by reference (such as
QList::constLast()), no extension happens and we end up with a dangling
reference.

cmakebuildconfiguration.cpp:1473:25: warning: possibly dangling reference to a temporary [-Wdangling-reference]
cmakebuildconfiguration.cpp:1473:61: note: the temporary was destroyed at the end of the full expression ‘ProjectExplorer::BuildStepList::steps() const().QList<ProjectExplorer::BuildStep*>::constLast()’

Change-Id: I3b169860d8bd41e9be6bfffd1757167b7348be9b
Reviewed-by: Eike Ziller <eike.ziller@qt.io>
Reviewed-by: hjk <hjk@qt.io>
Reviewed-by: Ville Voutilainen <ville.voutilainen@qt.io>

src/plugins/cmakeprojectmanager/cmakebuildconfiguration.cpp

@@ -1476,7 +1476,7 @@ CMakeBuildConfiguration::CMakeBuildConfiguration(Target *target, Id id)
         // Android magic:
         if (DeviceTypeKitAspect::deviceTypeId(k) == Android::Constants::ANDROID_DEVICE_TYPE) {
             buildSteps()->appendStep(Android::Constants::ANDROID_BUILD_APK_ID);
-            const auto &bs = buildSteps()->steps().constLast();
+            const auto bs = buildSteps()->steps().constLast();
             cmd.addArg("-DANDROID_PLATFORM:STRING="
                    + bs->data(Android::Constants::AndroidNdkPlatform).toString());
             auto ndkLocation = bs->data(Android::Constants::NdkLocation).value<FilePath>();

src/plugins/texteditor/texteditor.cpp

@@ -2905,9 +2905,9 @@ void TextEditorWidget::insertCodeSnippet(const QTextCursor &cursor_arg,
     d->m_document->autoIndent(cursor);
     cursor.endEditBlock();
 
-    const QColor &occurrencesColor
+    const QColor occurrencesColor
         = textDocument()->fontSettings().toTextCharFormat(C_OCCURRENCES).background().color();
-    const QColor &renameColor
+    const QColor renameColor
         = textDocument()->fontSettings().toTextCharFormat(C_OCCURRENCES_RENAME).background().color();
 
     for (const CursorPart &part : cursorParts) {

src/plugins/texteditor/textmark.cpp

@@ -132,7 +132,7 @@ void TextMark::paintAnnotation(QPainter &painter,
     const QColor &markColor = annotationColor();
 
     const FontSettings &fontSettings = m_baseTextDocument->fontSettings();
-    const AnnotationColors &colors = AnnotationColors::getAnnotationColors(
+    const AnnotationColors colors = AnnotationColors::getAnnotationColors(
                 markColor.isValid() ? markColor : painter.pen().color(),
                 fontSettings.toTextCharFormat(C_TEXT).background().color());
 

src/plugins/valgrind/callgrindvisualisation.cpp

@@ -155,7 +155,7 @@ void FunctionGraphicsItem::paint(QPainter *painter,
     painter->save();
 
     QRectF rect = this->rect();
-    const QColor &color = brush().color();
+    const QColor color = brush().color();
     if (option->state & QStyle::State_Selected) {
         QLinearGradient gradient(0, 0, rect.width(), 0);
         gradient.setColorAt(0, color.darker(100));