Bump firebase-functions-test from 0.3.3 to 2.1.0 in /functions

Bumps [firebase-functions-test](https://github.com/firebase/firebase-functions-test) from 0.3.3 to 2.1.0.
- [Release notes](https://github.com/firebase/firebase-functions-test/releases)
- [Changelog](https://github.com/firebase/firebase-functions-test/blob/master/tsconfig.release.json)
- [Commits](firebase/firebase-functions-test@v0.3.3...v2.1.0)

---
updated-dependencies:
- dependency-name: firebase-functions-test
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

functions/package-lock.json

@@ -23,7 +23,7 @@
   "devDependencies": {
     "eslint": "^8.31.0",
     "eslint-plugin-promise": "^6.0.0",
-    "firebase-functions-test": "^0.3.3"
+    "firebase-functions-test": "^2.1.0"
   },
   "private": true
 }