Hide tardiness-chip from lesson-notes if no student is late

aleksis/apps/alsijil/frontend/components/coursebook/documentation/LessonNotes.vue

@@ -65,7 +65,7 @@ import TardinessChip from "../personal_notes/TardinessChip.vue";
       </template>
     </extra-mark-chip>
 
-    <tardiness-chip>
+    <tardiness-chip v-if="tardyParticipations.length > 0">
       {{ $t("alsijil.personal_notes.late") }}
 
       <template #append>