Update pubspec.yaml

Author: kevmoo

pubspec.yaml

@@ -21,7 +21,7 @@ dependencies:
 dev_dependencies:
   build_runner: ^2.0.0
   build_test: ^2.0.0
-  lints: ">=2.0.0 <5.0.0"
+  lints: ^4.0.0
   mockito: ^5.0.0
   path: ^1.8.0
   test: ^1.16.0