Remove unnecessary async from closeModal()

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/stores/modal.ts

@@ -27,7 +27,7 @@ export const useModalStore = defineStore("modalStore", {
       this.whichModal = whichModal;
     },
     /** Closes the currently open modal. */
-    async closeModal() {
+    closeModal() {
       this.isModalOpen = false;
     },
   },