They're not deprecated, I choose to use new enums so it was more obvious as to what was what.  Ie using RESPONSE_SAVE vs GTK_RESPONSE_OK or GTK_RESPONSE_ACCEPT or GTK_RESPONSE_APPLY.  If we'd rather go that route we can, this just seemed like a better alternative.
The actual deprecated function is gtk_dialog_get_action_area which was/is used by pidgin_dialog_add_button, so I replaced the pidgin_dialog_add_button usage with gtk_dialog_add_button which uses the responses.