Give the section delegates a fixed height

This fixes the issue where the first printer would be drawn over the section label

CURA-6011

resources/qml/PrinterSelector/MachineSelectorList.qml

@@ -18,7 +18,7 @@ ListView
     {
         text: section == "true" ? catalog.i18nc("@label", "Connected printers") : catalog.i18nc("@label", "Preset printers")
         width: parent.width
-        height: visible ? contentHeight + 2 * UM.Theme.getSize("default_margin").height : 0
+        height: UM.Theme.getSize("action_button").height
         leftPadding: UM.Theme.getSize("default_margin").width
         renderType: Text.NativeRendering
         font: UM.Theme.getFont("medium")