chore: bump autoprefixer in /examples/openfeature_react/react-app

Bumps [autoprefixer](https://github.com/postcss/autoprefixer) from 10.4.20 to 10.4.21.
- [Release notes](https://github.com/postcss/autoprefixer/releases)
- [Changelog](https://github.com/postcss/autoprefixer/blob/main/CHANGELOG.md)
- [Commits](postcss/autoprefixer@10.4.20...10.4.21)

---
updated-dependencies:
- dependency-name: autoprefixer
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

examples/openfeature_react/react-app/package-lock.json

@@ -23,7 +23,7 @@
     "@typescript-eslint/eslint-plugin": "^8.26.0",
     "@typescript-eslint/parser": "^8.25.0",
     "@vitejs/plugin-react": "^4.3.4",
-    "autoprefixer": "^10.4.20",
+    "autoprefixer": "^10.4.21",
     "eslint": "^9.21.0",
     "eslint-plugin-react-hooks": "^5.2.0",
     "eslint-plugin-react-refresh": "^0.4.19",