Replace static_casts by QOverload where possible

Mainly to get rid of the QProcess::finished deprecation warning.

Also adjust coding style in the surrounding connects when needed.

Change-Id: I12f9b248c7974b892c4a069356e578e80f8c59e9
Reviewed-by: Christian Stenger <christian.stenger@qt.io>

src/plugins/qmakeprojectmanager/qmakestep.cpp

@@ -561,7 +561,7 @@ QMakeStepConfigWidget::QMakeStepConfigWidget(QMakeStep *step)
     connect(m_ui->qmakeAdditonalArgumentsLineEdit, &QLineEdit::textEdited,
             this, &QMakeStepConfigWidget::qmakeArgumentsLineEdited);
     connect(m_ui->buildConfigurationComboBox,
-            static_cast<void (QComboBox::*)(int)>(&QComboBox::currentIndexChanged),
+            QOverload<int>::of(&QComboBox::currentIndexChanged),
             this, &QMakeStepConfigWidget::buildConfigurationSelected);
     connect(m_ui->qmlDebuggingLibraryCheckBox, &QCheckBox::toggled,
             this, &QMakeStepConfigWidget::linkQmlDebuggingLibraryChecked);