chore(deps): bump built_value_generator

Bumps the built_value_generator group in /packages/aft with 1 update: [built_value_generator](https://github.com/google/built_value.dart).


Updates `built_value_generator` from 8.10.1 to 8.12.0
- [Release notes](https://github.com/google/built_value.dart/releases)
- [Changelog](https://github.com/google/built_value.dart/blob/master/CHANGELOG.md)
- [Commits](https://github.com/google/built_value.dart/commits)

---
updated-dependencies:
- dependency-name: built_value_generator
  dependency-version: 8.12.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: built_value_generator
...

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

Author: dependabot[bot]

packages/aft/pubspec.yaml

@@ -9,15 +9,15 @@ environment:
 dependencies:
   args: ^2.5.0
   async: ^2.10.0
-  aws_common: ">=0.4.2+5 <0.5.0"
+  aws_common: ^0.7.10
   built_collection: ^5.0.0
-  built_value: ^8.10.1
+  built_value: ^8.12.0
   checked_yaml: ^2.0.0
   cli_util: ^0.4.2
   code_builder: ^4.10.1
   collection: ^1.18.0
   file: ^7.0.1
-  git: ^2.2.0
+  git: ^2.3.2
   glob: ^2.1.0
   graphs: ^2.1.0
   io: ^1.0.4
@@ -35,7 +35,7 @@ dependencies:
   pubspec_parse: ^1.2.2
   shelf: ^1.4.0
   shelf_static: ^1.1.1
-  smithy: ">=0.4.0+8 <0.5.0"
+  smithy: ^0.7.8
   smithy_codegen:
     path: ../smithy/smithy_codegen
   stream_transform: ^2.1.0
@@ -64,11 +64,11 @@ dependency_overrides:
     path: ../smithy/smithy_codegen
 
 dev_dependencies:
-  amplify_lints: ^3.1.0
-  build_runner: ^2.4.9
-  built_value_generator: ^8.10.1
+  amplify_lints: ^3.1.3
+  build_runner: ^2.8.0
+  built_value_generator: ^8.12.0
   checks: ^0.3.0
-  json_serializable: ">=6.9.4 <6.10.0"
+  json_serializable: ^6.11.1
   test: ^1.22.1
   test_descriptor: ^2.0.1