chore(deps): update dependency vitest to v4 (#162)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

packages/sanity-sveltekit/package.json

@@ -56,7 +56,7 @@
     "svelte-check": "^4.3.3",
     "typescript": "^5.9.3",
     "vite": "^7.1.12",
-    "vitest": "^3.2.4"
+    "vitest": "^4.0.3"
   },
   "peerDependencies": {
     "@sveltejs/kit": "^2.16.1",