chore: 960 - refreshed pubspec.yaml, again (#1024)

Author: monsieurtanuki

pubspec.yaml

@@ -17,7 +17,7 @@ dependencies:
 dev_dependencies:
   analyzer: 6.11.0
   build_runner: 2.4.9
-  json_serializable: 6.9.0
+  json_serializable: 6.8.0
   lints: ">=3.0.0 <5.0.0"
   test: 1.25.5
   coverage: 1.8.0