Use wxID_HIGHEST instead of wxID_HIGHEST+1 in samples

There is no need to add 1 any more since the changes of 99c52403f9 (Use
usual half-open interval for wxID_LOWEST..wxID_HIGHEST, 2022-10-23), so
don't.

Closes #22923.

samples/artprov/arttest.cpp

@@ -60,7 +60,7 @@ private:
 enum
 {
     ID_Quit = wxID_EXIT,
-    ID_Logs = wxID_HIGHEST+1,
+    ID_Logs = wxID_HIGHEST,
     ID_Browser,
     ID_PlugProvider
 };