Bump firebase_core from 2.24.2 to 2.25.4 in /experimental/web_dashboard

Bumps [firebase_core](https://github.com/firebase/flutterfire/tree/master/packages/firebase_core) from 2.24.2 to 2.25.4.
- [Release notes](https://github.com/firebase/flutterfire/releases)
- [Changelog](https://github.com/firebase/flutterfire/blob/master/CHANGELOG.md)
- [Commits](https://github.com/firebase/flutterfire/commits/firebase_core-v2.25.4/packages/firebase_core)

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

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

experimental/web_dashboard/pubspec.yaml

@@ -12,7 +12,7 @@ dependencies:
   community_charts_flutter: ^1.0.2
   cupertino_icons: ^1.0.0
   firebase_auth: ^4.0.1
-  firebase_core: ^2.0.0
+  firebase_core: ^2.25.4
   flutter:
     sdk: flutter
   google_sign_in: ^6.0.0