chore(deps): bump serialize-javascript and mocha in /functions (#490)

Bumps [serialize-javascript](https://github.com/yahoo/serialize-javascript) to 6.0.2 and updates ancestor dependency [mocha](https://github.com/mochajs/mocha). These dependencies need to be updated together.


Updates `serialize-javascript` from 6.0.0 to 6.0.2
- [Release notes](https://github.com/yahoo/serialize-javascript/releases)
- [Commits](yahoo/serialize-javascript@v6.0.0...v6.0.2)

Updates `mocha` from 10.2.0 to 10.8.2
- [Release notes](https://github.com/mochajs/mocha/releases)
- [Changelog](https://github.com/mochajs/mocha/blob/main/CHANGELOG.md)
- [Commits](mochajs/mocha@v10.2.0...v10.8.2)

---
updated-dependencies:
- dependency-name: serialize-javascript
  dependency-version: 6.0.2
  dependency-type: indirect
- dependency-name: mocha
  dependency-version: 10.8.2
  dependency-type: direct:development
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

functions/package-lock.json

@@ -30,7 +30,7 @@
     "eslint-config-google": "^0.14.0",
     "eslint-plugin-import": "^2.25.4",
     "firebase-functions-test": "^3.1.0",
-    "mocha": "^10.2.0",
+    "mocha": "^10.8.2",
     "sinon": "^15.0.4",
     "ts-mocha": "^10.0.0",
     "typescript": "^4.9.0"