Update vitest to v2.1.9

Author: MelissaAutumn

frontend/package-lock.json

@@ -54,7 +54,7 @@
     "postcss-nesting": "^13.0.0",
     "typescript": "^5.5.3",
     "vite-plugin-eslint": "^1.8.1",
-    "vitest": "^2.1.1"
+    "vitest": "^2.1.9"
   },
   "postcss": {
     "plugins": {