Bump pigeon in /examples/development/platform_integration

Bumps [pigeon](https://github.com/flutter/packages/tree/main/packages) from 5.0.1 to 8.0.0.
- [Release notes](https://github.com/flutter/packages/releases)
- [Commits](https://github.com/flutter/packages/commits/pigeon-v8.0.0/packages)

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

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

Author: dependabot[bot]

examples/development/platform_integration/pubspec.yaml

@@ -29,7 +29,7 @@ environment:
 dependencies:
   flutter:
     sdk: flutter
-  pigeon: ^7.0.0
+  pigeon: ^8.0.0
 
 
   # The following adds the Cupertino Icons font to your application.