Re-Add endpoint to update individual lessons

aleksis/apps/lesrooster/schema/__init__.py

@@ -425,6 +425,8 @@ class Mutation(graphene.ObjectType):
     delete_lesson_bundles = LessonBundleBatchDeleteMutation.Field()
     update_lesson_bundles = LessonBundleBatchPatchMutation.Field()
 
+    update_lessons = LessonBatchPatchMutation.Field()
+
     create_supervisions = SupervisionBatchCreateMutation.Field()
     delete_supervisions = SupervisionBatchDeleteMutation.Field()
     update_supervisions = SupervisionBatchPatchMutation.Field()