upgrade to qt 6 compliance

app/widget/taskview/elapsedcounterwidget.cpp

@@ -34,7 +34,7 @@ ElapsedCounterWidget::ElapsedCounterWidget(QWidget* parent) :
 {
   QHBoxLayout* layout = new QHBoxLayout(this);
   layout->setSpacing(layout->spacing() * 8);
-  layout->setMargin(0);
+  layout->setContentsMargins(0, 0, 0, 0);
 
   elapsed_lbl_ = new QLabel();
   layout->addWidget(elapsed_lbl_);

app/widget/taskview/taskview.cpp

@@ -37,7 +37,7 @@ TaskView::TaskView(QWidget* parent) :
   // Create layout for central widget
   layout_ = new QVBoxLayout(central_widget_);
   layout_->setSpacing(0);
-  layout_->setMargin(0);
+  layout_->setContentsMargins(0, 0, 0, 0);
 
   // Add a "stretch" so that TaskViewItems don't try to expand all the way to the bottom
   layout_->addStretch();