Bump json_serializable from 6.5.0 to 6.5.3 in /app_dart (#2238)

diff --git a/app_dart/pubspec.lock b/app_dart/pubspec.lock
index 7d174b1..f08858d 100644
--- a/app_dart/pubspec.lock
+++ b/app_dart/pubspec.lock
@@ -392,7 +392,7 @@
       name: json_serializable
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "6.5.0"
+    version: "6.5.3"
   lints:
     dependency: transitive
     description:
diff --git a/app_dart/pubspec.yaml b/app_dart/pubspec.yaml
index 0d300b8..fca94d4 100644
--- a/app_dart/pubspec.yaml
+++ b/app_dart/pubspec.yaml
@@ -37,7 +37,7 @@
   build_runner: ^2.3.2
   fake_async: ^1.3.1
   flutter_lints: ^1.0.4
-  json_serializable: ^6.5.0
+  json_serializable: ^6.5.3
   mockito: ^5.2.0
   platform: ^3.1.0
   process: ^4.2.4