[PlasmaComponents3] Strip mnemonic ampersands from tooltip text

They're never useful in that context, and this prevents having to strip
them out manually when assigning a tooltip text that comes from a source
that sets a mnemonic ampersand. For example
https://invent.kde.org/plasma/plasma-workspace/-/merge_requests/171#note_79871

src/declarativeimports/plasmacomponents3/ToolTip.qml

@@ -45,7 +45,9 @@ T.ToolTip {
     closePolicy: T.Popup.CloseOnEscape | T.Popup.CloseOnPressOutsideParent | T.Popup.CloseOnReleaseOutsideParent
 
     contentItem: Label {
-        text: control.text
+        // Strip out ampersands right before non-whitespace characters, i.e.
+        // those used to determine the alt key shortcut
+        text: control.text.replace(/&(?=\S)/g, "")
         font: control.font
         color: PlasmaCore.ColorScope.textColor
     }