[geolocator]: Bump flutter_lints in /geolocator/example

Bumps [flutter_lints](https://github.com/flutter/packages/tree/main/packages) from 5.0.0 to 6.0.0.
- [Release notes](https://github.com/flutter/packages/releases)
- [Commits](https://github.com/flutter/packages/commits/flutter_lints-v6.0.0/packages)

---
updated-dependencies:
- dependency-name: flutter_lints
  dependency-version: 6.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

geolocator/example/pubspec.yaml

@@ -33,7 +33,7 @@ dependencies:
 dev_dependencies:
   flutter_test:
     sdk: flutter
-  flutter_lints: ^5.0.0
+  flutter_lints: ^6.0.0
 
 # For information on the generic Dart part of this file, see the
 # following page: https://dart.dev/tools/pub/pubspec