build(deps-dev): bump vitest from 3.2.4 to 4.1.5 in /playground

Bumps [vitest](https://github.com/vitest-dev/vitest/tree/HEAD/packages/vitest) from 3.2.4 to 4.1.5.
- [Release notes](https://github.com/vitest-dev/vitest/releases)
- [Commits](https://github.com/vitest-dev/vitest/commits/v4.1.5/packages/vitest)

---
updated-dependencies:
- dependency-name: vitest
  dependency-version: 4.1.5
  dependency-type: direct:development
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

playground/package.json

@@ -52,6 +52,6 @@
     "typescript": "^6.0.2",
     "vite": "^7.3.2",
     "vite-tsconfig-paths": "^5.1.4",
-    "vitest": "^3.2.4"
+    "vitest": "^4.1.5"
   }
 }