fix(deps): bump firebase from 9.20.0 to 9.21.0 in /web

Bumps [firebase](https://github.com/firebase/firebase-js-sdk) from 9.20.0 to 9.21.0.
- [Release notes](https://github.com/firebase/firebase-js-sdk/releases)
- [Changelog](https://github.com/firebase/firebase-js-sdk/blob/master/CHANGELOG.md)
- [Commits](https://github.com/firebase/firebase-js-sdk/compare/[email protected]@9.21.0)

---
updated-dependencies:
- dependency-name: firebase
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

web/package-lock.json

@@ -29,7 +29,7 @@
     "core-js": "^3.30.1",
     "date-fns": "^2.29.3",
     "dotenv": "^16.0.3",
-    "firebase": "^9.20.0",
+    "firebase": "^9.21.0",
     "firebaseui": "^6.0.2",
     "libphonenumber-js": "^1.10.28",
     "nuxt": "^2.16.3",