Emit event when substitution is emtied & does not contain oldId

aleksis/apps/chronos/frontend/components/substitutions/SubstitutionCard.vue

@@ -209,7 +209,7 @@ import deleteMixin from "aleksis.core/mixins/deleteMixin.js";
 <script>
 export default {
   name: "SubstitutionCard",
-  emits: ["open", "close"],
+  emits: ["open", "close", "delete"],
   mixins: [createOrPatchMixin, deleteMixin],
   data() {
     return {
@@ -259,7 +259,7 @@ export default {
             cached[index].id = cached[index].oldId;
             cached[index].oldId = null;
           } else {
-            cached.splice(index, 1);
+            this.$emit("delete");
           }
         }
         return cached;