Bump pigeon from 3.1.5 to 3.1.6

Bumps [pigeon](https://github.com/flutter/packages/tree/main/packages) from 3.1.5 to 3.1.6.
- [Release notes](https://github.com/flutter/packages/releases)
- [Commits](https://github.com/flutter/packages/commits/pigeon-v3.1.6/packages)

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

Signed-off-by: dependabot[bot] <support@github.com>

pubspec.lock

@@ -408,7 +408,7 @@ packages:
       name: pigeon
       url: "https://pub.dartlang.org"
     source: hosted
-    version: "3.1.5"
+    version: "3.1.6"
   platform:
     dependency: transitive
     description:

pubspec.yaml

@@ -70,7 +70,7 @@ dev_dependencies:
   build_runner: ^2.1.4
   freezed: ^2.0.3
   json_serializable: ^6.0.0
-  pigeon: ^3.0.3
+  pigeon: ^3.1.6
 
 # For information on the generic Dart part of this file, see the
 # following page: https://dart.dev/tools/pub/pubspec