build(deps): bump firebase from 9.15.0 to 9.21.0

Bumps [firebase](https://github.com/firebase/firebase-js-sdk) from 9.15.0 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/firebase@9.15.0...firebase@9.21.0)

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

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

Author: dependabot[bot]

package.json

@@ -19,7 +19,7 @@
     "@emotion/styled": "^11.10.5",
     "date-fns": "^2.29.3",
     "date-fns-tz": "^1.3.7",
-    "firebase": "^9.13.0",
+    "firebase": "^9.21.0",
     "framer-motion": "^8.4.3",
     "next": "^13.3.0",
     "react": "^18.2.0",