build(deps-dev): bump @types/firebase-token-generator

Bumps [@types/firebase-token-generator](https://github.com/DefinitelyTyped/DefinitelyTyped/tree/HEAD/types/firebase-token-generator) from 2.0.30 to 2.0.31.
- [Release notes](https://github.com/DefinitelyTyped/DefinitelyTyped/releases)
- [Commits](https://github.com/DefinitelyTyped/DefinitelyTyped/commits/HEAD/types/firebase-token-generator)

---
updated-dependencies:
- dependency-name: "@types/firebase-token-generator"
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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