wallpapers/image: Fix missing folder action buttons

The width of the action area needs to be substracted in contentItem's
width.

Also use `Kirigami.Units.gridUnit * 4` because `overlayWidth` was
introduced in Frameworks 5.94, and people using Plasma 5.24 may have an
older Frameworks version.

wallpapers/image/imagepackage/contents/ui/config.qml

@@ -331,6 +331,7 @@ ColumnLayout {
                             // Don't need a highlight or hover effects
                             hoverEnabled: false
                             contentItem: Kirigami.BasicListItem {
+                                width: slidePathsView.width - (parent.hasOwnProperty("overlayWidth") ? overlayWidth : Kirigami.Units.gridUnit * 4)
                                 // Don't need a highlight or hover effects
                                 hoverEnabled: false
                                 separatorVisible: false