fix(timetable): hover icon visible when no onClick action (#3970)

Co-authored-by: Kok Rui Wong <[email protected]>

Author: leslieyip02

website/src/views/timetable/TimetableCell.tsx

@@ -140,6 +140,7 @@ const TimetableCell: React.FC<Props> = (props) => {
           </div>
 
           {lesson.isTaInTimetable &&
+            onClick &&
             isHoveredOver &&
             hoverLesson &&
             (lesson.isActive || !lesson.isOptionInTimetable ? (