Update to latest lints and cleanup (dart-lang/string_scanner#67)

pkgs/string_scanner/analysis_options.yaml

diff --git a/pkgs/string_scanner/analysis_options.yaml b/pkgs/string_scanner/analysis_options.yaml
index 0b97591..813466b 100644
--- a/pkgs/string_scanner/analysis_options.yaml
+++ b/pkgs/string_scanner/analysis_options.yaml
@@ -13,27 +13,21 @@
     - avoid_classes_with_only_static_members
     - avoid_private_typedef_functions
     - avoid_redundant_argument_values
-    - avoid_returning_null_for_future
     - avoid_returning_this
     - avoid_unused_constructor_parameters
     - avoid_void_async
     - cancel_subscriptions
-    - comment_references
     - join_return_with_assignment
     - literal_only_boolean_expressions
     - missing_whitespace_between_adjacent_strings
     - no_adjacent_strings_in_list
     - no_runtimeType_toString
     - package_api_docs
-    - prefer_const_constructors
     - prefer_const_declarations
     - prefer_expression_function_bodies
     - prefer_final_locals
-    - prefer_relative_imports
-    - test_types_in_equals
     - unnecessary_await_in_return
     - unnecessary_raw_strings
     - use_if_null_to_convert_nulls_to_bools
     - use_raw_strings
     - use_string_buffers
-    - use_super_parameters

pkgs/string_scanner/pubspec.yaml

diff --git a/pkgs/string_scanner/pubspec.yaml b/pkgs/string_scanner/pubspec.yaml
index 40682ec..7ceb7d9 100644
--- a/pkgs/string_scanner/pubspec.yaml
+++ b/pkgs/string_scanner/pubspec.yaml
@@ -10,5 +10,5 @@
   source_span: ^1.8.0
 
 dev_dependencies:
-  dart_flutter_team_lints: ^1.0.0
+  dart_flutter_team_lints: ^2.0.0
   test: ^1.16.0