ui: Fix race condition where refresh can occurs before deletion

ui/src/routes/works/[wid]/+page.svelte

@@ -123,7 +123,7 @@
                                     <button
                                         class="btn btn-sm btn-danger mx-1"
                                         title="Supprimer la note"
-                                        on:click={() => { grade.delete(); refresh_grades(w); }}
+                                        on:click={() => { grade.delete().then(() => refresh_grades(w)); }}
                                     >
                                         <i class="bi bi-trash"></i>
                                     </button>