Bump @firebase/util from 1.3.0 to 1.4.0

Bumps [@firebase/util](https://github.com/firebase/firebase-js-sdk/tree/HEAD/packages/util) from 1.3.0 to 1.4.0.
- [Release notes](https://github.com/firebase/firebase-js-sdk/releases)
- [Changelog](https://github.com/firebase/firebase-js-sdk/blob/master/packages/util/CHANGELOG.md)
- [Commits](https://github.com/firebase/firebase-js-sdk/commits/@firebase/util@1.4.0/packages/util)

---
updated-dependencies:
- dependency-name: "@firebase/util"
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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