Make wxRect parameter of wxRichToolTip::ShowFor() const.

This parameter is read-only, so accept a const pointer here.

See #15060.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@73589 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/richtooltip.h

@@ -88,7 +88,7 @@ public:
     void SetTitleFont(const wxFont& font);
 
     // Show the tooltip for the given window and optionally a specified area.
-    void ShowFor(wxWindow* win, wxRect* rect = NULL);
+    void ShowFor(wxWindow* win, const wxRect* rect = NULL);
 
     // Non-virtual dtor as this class is not supposed to be derived from.
     ~wxRichToolTip();