Adapt deletion of substitutions to CRUD refactoring

aleksis/apps/chronos/frontend/components/AmendLesson.vue

@@ -69,10 +69,10 @@
     </dialog-object-form>
     <delete-dialog
       deleteSuccessMessageI18nKey="chronos.event.amend.delete_success"
-      :gql-mutation="gqlDeleteMutation"
+      :gql-delete-mutation="gqlDeleteMutation"
       v-model="deleteEvent"
-      :item="selectedEvent.meta"
-      @success="updateOnSave()"
+      :items="[selectedEvent.meta]"
+      @save="updateOnSave()"
       >
       <template #title>
         {{ $t("chronos.event.amend.delete_dialog") }}

aleksis/apps/chronos/frontend/components/amendLesson.graphql

@@ -69,7 +69,7 @@ mutation patchAmendLessons($input: [BatchPatchLessonEventInput]!) {
 }
 
 mutation deleteAmendLessons($ids: [ID]!) {
-  deleteAmendLesson(ids: $ids) {
+  deleteAmendLessons(ids: $ids) {
     deletionCount
   }
 }