fix: bump lints from 4.0.0 to 5.1.0 (#14)

Bumps [lints](https://github.com/dart-lang/lints) from 4.0.0 to 5.1.0.
- [Release notes](https://github.com/dart-lang/lints/releases)
- [Changelog](https://github.com/dart-lang/lints/blob/main/CHANGELOG.md)
- [Commits](dart-archive/lints@v4.0.0...v5.1.0)

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

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

pubspec.yaml

@@ -8,5 +8,5 @@ environment:
   sdk: "<4.0.0"
 
 dev_dependencies:
-  lints: ">=3.0.0 <5.0.0"
+  lints: ">=3.0.0 <6.0.0"
   test: ^1.21.0