Remove obsolete usage of EventIncident

The default Gaudi Incident class now provides the same features as the ATLAS specific EventIncident, i.e. the access to the EventContext. This MR removes the remaining client uses of EventIncident from the code base (see also !20723 (comment 2304746)). In all cases the dynamic_cast<EventIncident> check was entirely useless as the client only subscribed to event-based incidents to begin with.

The next step would be to change all EventLoopMgrs to fire a Gaudi Incident instead of EventIncident.

cc @tsulaia