use smaller font size in time table

lib/timetable/lesson.dart

@@ -22,7 +22,6 @@ class LessonWidget extends StatelessWidget {
   String get text => [
         lesson.lecture.name,
         lesson.rooms.firstOrNull?.name ?? '(Kein Raum)',
-        lesson.teachers.first.name,
       ].join('\n');
 
   const LessonWidget({
@@ -66,9 +65,7 @@ class LessonWidget extends StatelessWidget {
                     child: Text(
                       text,
                       textAlign: TextAlign.center,
-                      style: TextStyle(
-                        color: Theme.of(context).colorScheme.onPrimary,
-                      ),
+                      style: Theme.of(context).primaryTextTheme.bodySmall!,
                     ),
                   ),
                 ),