Fix combobox breakage

Summary:
https://cgit.kde.org/plasma-framework.git/commit/?id=a21bc11fe11651f6d211489ebfc8435cef877194 erroneously added `renderType` properties to PlasmaComponents3 ComboBoxes, but QML ComboBoxes don't have this property, which broke Latte Dock's settings. This patch removes it.

BUG: 392026

Test Plan:
- Deployed, added Latte Dock, ran Plasmashell with and without `PLASMA_USE_QT_SCALING=1`, and with and without a HiDPI scale factor
- Opened Latte Dock's settings window. In all cases, Latte Dock's settings window appeared normally and all comboboxes rendered properly
- Opened Folder View settings and verified that all ComboBoxes there looked and worked fine, too

Reviewers: broulik, #plasma, mvourlakos, davidedmundson

Reviewed By: #plasma, davidedmundson

Subscribers: #frameworks

Tags: #frameworks

Differential Revision: https://phabricator.kde.org/D11484

src/declarativeimports/plasmacomponents3/ComboBox.qml

@@ -39,10 +39,6 @@ T.ComboBox {
     rightPadding: surfaceNormal.margins.right
     bottomPadding: surfaceNormal.margins.bottom
 
-    // Work around Qt bug where NativeRendering breaks for non-integer scale factors
-    // https://bugreports.qt.io/browse/QTBUG-67007
-    renderType: Screen.devicePixelRatio % 1 !== 0 ? Text.QtRendering : Text.NativeRendering
-
     delegate: ItemDelegate {
         width: control.popup.width
         text: control.textRole ? (Array.isArray(control.model) ? modelData[control.textRole] : model[control.textRole]) : modelData

src/declarativeimports/plasmastyle/ComboBoxStyle.qml

@@ -29,10 +29,6 @@ import "private" as Private
 QtQuickControlStyle.ComboBoxStyle {
     drowDownButtonWidth: units.iconSizes.small
 
-    // Work around Qt bug where NativeRendering breaks for non-integer scale factors
-    // https://bugreports.qt.io/browse/QTBUG-67007
-    renderType: Screen.devicePixelRatio % 1 !== 0 ? Text.QtRendering : Text.NativeRendering
-
     label: PlasmaComponents.Label {
         text: control.currentText
         elide: Text.ElideRight