Removed the alteration of status.hovering during Focus Enter and Focus Exit events.

This is incorrect and not fully implemented, and results in inconsistency in the UI and in the hovering variable.

(cherry-picked from commit edcbe88389)

scene/gui/base_button.cpp

@@ -98,17 +98,14 @@ void BaseButton::_notification(int p_what) {
 	}
 
 	if (p_what == NOTIFICATION_FOCUS_ENTER) {
-		status.hovering = true;
 		update();
 	}
 
 	if (p_what == NOTIFICATION_FOCUS_EXIT) {
 		if (status.press_attempt) {
 			status.press_attempt = false;
-			status.hovering = false;
 			update();
 		} else if (status.hovering) {
-			status.hovering = false;
 			update();
 		}
 	}