chore(deps): update dependency vitest to v4

Author: renovate[bot]

package.json

@@ -58,7 +58,7 @@
     "openapi-fetch": "^0.15.0",
     "openapi-typescript": "^7.6.1",
     "typescript": "^5.8.3",
-    "vitest": "^3.1.1"
+    "vitest": "^4.0.0"
   },
   "peerDependencies": {
     "@biomejs/biome": ">=1.9.4",