Bump googleapis from 12.0.0 to 13.1.0 in /examples/googleapis

Bumps [googleapis](https://github.com/google/googleapis.dart/tree/master/generated) from 12.0.0 to 13.1.0.
- [Release notes](https://github.com/google/googleapis.dart/releases)
- [Commits](https://github.com/google/googleapis.dart/commits/googleapis-v13.1.0/generated)

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

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

examples/googleapis/pubspec.yaml

@@ -10,7 +10,7 @@ dependencies:
   flutter:
     sdk: flutter
   google_sign_in: ^6.2.1
-  googleapis: ^12.0.0
+  googleapis: ^13.1.0
   http: ^1.2.0
 
 dev_dependencies: