chore(deps): update devdependency @nuxt/test-utils to v3.21.0 (#874)

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

Author: renovate[bot]

package.json

@@ -77,7 +77,7 @@
     "@nuxt/eslint-config": "1.11.0",
     "@nuxt/module-builder": "1.0.2",
     "@nuxt/schema": "4.2.1",
-    "@nuxt/test-utils": "3.20.1",
+    "@nuxt/test-utils": "3.21.0",
     "@types/node": "24.10.1",
     "@vitest/coverage-v8": "3.2.4",
     "@vue/test-utils": "2.4.6",