build(deps-dev): Bump the vitest group across 2 directories with 3 updates

Bumps the vitest group with 1 update in the / directory: [@vitest/coverage-istanbul](https://github.com/vitest-dev/vitest/tree/HEAD/packages/coverage-istanbul).
Bumps the vitest group with 2 updates in the /build/frontend-legacy directory: [vitest](https://github.com/vitest-dev/vitest/tree/HEAD/packages/vitest) and [@vitest/coverage-v8](https://github.com/vitest-dev/vitest/tree/HEAD/packages/coverage-v8).


Updates `@vitest/coverage-istanbul` from 4.0.15 to 4.0.16
- [Release notes](https://github.com/vitest-dev/vitest/releases)
- [Commits](https://github.com/vitest-dev/vitest/commits/v4.0.16/packages/coverage-istanbul)

Updates `vitest` from 4.0.15 to 4.0.16
- [Release notes](https://github.com/vitest-dev/vitest/releases)
- [Commits](https://github.com/vitest-dev/vitest/commits/v4.0.16/packages/vitest)

Updates `vitest` from 4.0.15 to 4.0.16
- [Release notes](https://github.com/vitest-dev/vitest/releases)
- [Commits](https://github.com/vitest-dev/vitest/commits/v4.0.16/packages/vitest)

Updates `@vitest/coverage-v8` from 4.0.15 to 4.0.16
- [Release notes](https://github.com/vitest-dev/vitest/releases)
- [Commits](https://github.com/vitest-dev/vitest/commits/v4.0.16/packages/coverage-v8)

---
updated-dependencies:
- dependency-name: "@vitest/coverage-istanbul"
  dependency-version: 4.0.16
  dependency-type: direct:development
  update-type: version-update:semver-patch
  dependency-group: vitest
- dependency-name: vitest
  dependency-version: 4.0.16
  dependency-type: direct:development
  update-type: version-update:semver-patch
  dependency-group: vitest
- dependency-name: vitest
  dependency-version: 4.0.16
  dependency-type: direct:development
  update-type: version-update:semver-patch
  dependency-group: vitest
- dependency-name: "@vitest/coverage-v8"
  dependency-version: 4.0.16
  dependency-type: direct:development
  update-type: version-update:semver-patch
  dependency-group: vitest
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

build/frontend-legacy/package-lock.json

@@ -113,7 +113,7 @@
     "@testing-library/user-event": "^14.6.1",
     "@testing-library/vue": "^5.8.3",
     "@vitejs/plugin-vue2": "^2.3.4",
-    "@vitest/coverage-v8": "^4.0.15",
+    "@vitest/coverage-v8": "^4.0.16",
     "@vue/test-utils": "^1.3.5",
     "@vue/tsconfig": "~0.5.1",
     "babel-loader-exclude-node-modules-except": "^1.2.1",
@@ -129,7 +129,7 @@
     "sass": "^1.97.1",
     "typescript": "^5.9.2",
     "vite": "^7.3.0",
-    "vitest": "^4.0.13",
+    "vitest": "^4.0.16",
     "vue-loader": "^15.11.1",
     "vue-template-compiler": "^2.7.16",
     "webpack": "^5.104.1",