Remove unused dart_code_linter dependency and dead rules config

tool/dart_skills_lint/analysis_options.yaml

@@ -15,9 +15,6 @@ analyzer:
     strict-casts: true
     strict-inference: true
     strict-raw-types: true
-  # dart_code_linter is intentionally NOT registered as an analyzer
-  # `plugin` here. When it was, `dart analyze` had racy false positives. 
-  # See https://github.com/flutter/agent-plugins/issues/144
   errors:
     # allow deprecated members (we do this because otherwise we have to annotate
     # every member in every test, assert, etc, when we or the Dart SDK deprecates
@@ -268,37 +265,4 @@ linter:
     - use_truncating_division
     - valid_regexps
     - void_checks
-
-dart_code_linter:
-  rules:
-    # Explicit typing
-    - avoid-dynamic
-    - avoid-unnecessary-type-assertions
-    - avoid-unnecessary-type-casts
-    - avoid-unrelated-type-assertions
-    - avoid-collection-methods-with-unrelated-types
-
-    # Predictable structure
-    - avoid-nested-conditional-expressions
-    - no-equal-then-else
-    - no-boolean-literal-compare
-    - no-empty-block
-    - avoid-redundant-async
-    - avoid-passing-async-when-sync-expected
-    # `late` for fields initialized in `setUp` is the idiomatic Dart test
-    # fixture pattern; enforce this rule on lib only.
-    - avoid-late-keyword:
-        exclude:
-          - test/**
-    - prefer-named-record-fields
-
-    # Clean up
-    - avoid-unused-parameters
-    - prefer-moving-to-variable
-    # Test files must be named `*_test.dart` for the test runner, and commonly
-    # hold several small fixture/mock classes, so they can never match this
-    # rule's "file name == first class name" convention. Enforce it on lib only.
-    - prefer-match-file-name:
-        exclude:
-          - test/**
-    - always-remove-listener
+

tool/dart_skills_lint/pubspec.yaml

@@ -34,7 +34,6 @@ dev_dependencies:
   json_serializable: ^6.7.0
   build_runner: ^2.4.0
   cognitive_complexity: ^0.2.0
-  dart_code_linter: ^4.0.3
   coverage: ^1.15.0
 
 executables: