update lints dependency (dart-lang/markdown#613)

diff --git a/pkgs/markdown/pubspec.yaml b/pkgs/markdown/pubspec.yaml
index da60194..d00fc17 100644
--- a/pkgs/markdown/pubspec.yaml
+++ b/pkgs/markdown/pubspec.yaml
@@ -22,7 +22,7 @@
   build_version: ^2.0.3
   build_web_compilers: ^4.0.0
   collection: ^1.15.0
-  dart_flutter_team_lints: ^2.0.0
+  dart_flutter_team_lints: ^3.0.0
   html: ^0.15.0
   http: ^1.0.0
   io: ^1.0.0