fix(deps): update dependency cloud_firestore to ^4.12.2 (#200)

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

pubspec.yaml

@@ -8,7 +8,7 @@ environment:
   sdk: ">=2.12.0 <3.0.0"
 
 dependencies:
-  cloud_firestore: ^4.0.0
+  cloud_firestore: ^4.12.2
   flutter:
     sdk: flutter
   shared_preferences: ^2.0.0