Port to Kirigami version of ContextualHelpButton

It's been added there after starting life in kcmutils. Depends on
https://invent.kde.org/frameworks/kirigami/-/merge_requests/1488.

src/kcms/rules/ui/RuleItemDelegate.qml

@@ -7,7 +7,7 @@
 import QtQuick
 import QtQuick.Layouts
 import QtQuick.Controls as QQC2
-import org.kde.kirigami 2.10 as Kirigami
+import org.kde.kirigami as Kirigami
 import org.kde.kcmutils as KCM
 
 QQC2.ItemDelegate {
@@ -56,7 +56,7 @@ QQC2.ItemDelegate {
                 QQC2.ToolTip.delay: Kirigami.Units.toolTipDelay
             }
 
-            KCM.ContextualHelpButton {
+            Kirigami.ContextualHelpButton {
                 Layout.alignment: Qt.AlignVCenter
                 visible: model.description.length > 0
                 toolTipText: model.description

src/kcms/rules/ui/RulesEditor.qml

@@ -7,7 +7,7 @@
 import QtQuick
 import QtQuick.Layouts
 import QtQuick.Controls as QQC2
-import org.kde.kirigami 2.19 as Kirigami
+import org.kde.kirigami as Kirigami
 import org.kde.kcmutils as KCM
 import org.kde.kitemmodels
 import org.kde.kcms.kwinrules
@@ -229,7 +229,7 @@ KCM.ScrollViewKCM {
                         }
                     }
 
-                    KCM.ContextualHelpButton {
+                    Kirigami.ContextualHelpButton {
                         Layout.rightMargin: Kirigami.Units.largeSpacing
                         visible: model.description.length > 0
                         toolTipText: model.description