Revert "[kcms/cursor] Port to required properties"

We can not use the required properties, because it breaks the property binding.
ec79af7396 apparently fixes that, however
it is not released as part of Qt6 or is part of the KDE patch collection.

This reverts commit f3293bc59e.

BUG: 453226


(cherry picked from commit 90d36545ea)

kcms/cursortheme/package/contents/ui/Delegate.qml

@@ -19,16 +19,10 @@ import org.kde.private.kcm_cursortheme 1.0
 KCM.GridDelegate {
     id: delegate
 
-    required property string description
-    required property string display
-    required property bool pendingDeletion
-    required property bool isWritable
-    required property int index
+    text: model.display
+    toolTip: model.description
 
-    text: display
-    toolTip: description
-
-    opacity: pendingDeletion ? 0.3 : 1
+    opacity: model.pendingDeletion ? 0.3 : 1
 
     thumbnailAvailable: true
     thumbnail: PreviewWidget {
@@ -43,7 +37,7 @@ KCM.GridDelegate {
         transformOrigin: Item.TopLeft
         scale: 1 / Screen.devicePixelRatio
         themeModel: kcm.cursorsModel
-        currentIndex: delegate.index
+        currentIndex: index
         currentSize: kcm.cursorThemeSettings.cursorSize
     }
 
@@ -58,15 +52,15 @@ KCM.GridDelegate {
         Kirigami.Action {
             iconName: "edit-delete"
             tooltip: i18n("Remove Theme")
-            enabled: delegate.isWritable
-            visible: !delegate.pendingDeletion
-            onTriggered: delegate.pendingDeletion = true
+            enabled: model.isWritable
+            visible: !model.pendingDeletion
+            onTriggered: model.pendingDeletion = true
         },
         Kirigami.Action {
             iconName: "edit-undo"
             tooltip: i18n("Restore Cursor Theme")
-            visible: delegate.pendingDeletion
-            onTriggered: delegate.pendingDeletion = false
+            visible: model.pendingDeletion
+            onTriggered: model.pendingDeletion = false
         }
     ]