chore(deps): update test packages to v4 (major) (#857)

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

Author: renovate[bot]

package.json

@@ -79,7 +79,7 @@
     "@nuxt/schema": "4.3.1",
     "@nuxt/test-utils": "4.0.0",
     "@types/node": "24.11.0",
-    "@vitest/coverage-v8": "3.2.4",
+    "@vitest/coverage-v8": "4.0.18",
     "@vue/test-utils": "2.4.6",
     "bumpp": "10.4.1",
     "eslint": "10.0.2",
@@ -93,7 +93,7 @@
     "typescript": "5.9.3",
     "unbuild": "3.6.1",
     "unhead": "2.1.10",
-    "vitest": "3.2.4",
+    "vitest": "4.0.18",
     "vue": "3.5.29",
     "vue-tsc": "3.2.5"
   },