Bump cloud_firestore in /experimental/web_dashboard (#1212)

Bumps [cloud_firestore](https://github.com/FirebaseExtended/flutterfire) from 3.1.13 to 3.1.14.
- [Release notes](https://github.com/FirebaseExtended/flutterfire/releases)
- [Changelog](https://github.com/firebase/flutterfire/blob/master/CHANGELOG.md)
- [Commits](https://github.com/FirebaseExtended/flutterfire/compare/cloud_firestore-v3.1.13...cloud_firestore_v3.1.14)

---
updated-dependencies:
- dependency-name: cloud_firestore
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

experimental/web_dashboard/pubspec.yaml

@@ -7,7 +7,7 @@ environment:
 dependencies:
   flutter:
     sdk: flutter
-  cloud_firestore: ^3.1.13
+  cloud_firestore: ^3.1.14
   cupertino_icons: ^1.0.0
   firebase_auth: ^3.3.17
   firebase_core: ^1.16.0