Update dependency dart_style to v3

Author: renovate[bot]

generator/pubspec.yaml

@@ -9,7 +9,7 @@ dependencies:
   build: ^1.2.2
   source_gen: ^0.9.5
   code_builder: ^3.2.1
-  dart_style: ^1.3.3
+  dart_style: ^3.0.0
   analyzer: ^0.39.5
   recase: ^3.0.0
   logging: ^0.11.4