Link to dart.dev for linter rules

This allows more flexibility as we can configure the redirect overtime, compared to the GitHub hosted site which we have less control over. It could even redirect to the old linter site in the meantime if desired.

Contributes to https://github.com/dart-lang/linter/issues/4411 and https://github.com/dart-lang/site-www/issues/4498

Change-Id: I3512002cdf7f62c0338d67cec0d7091f1166479d
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/307000
Reviewed-by: Phil Quitslund <pquitslund@google.com>
Commit-Queue: Phil Quitslund <pquitslund@google.com>
Reviewed-by: Brian Wilkerson <brianwilkerson@google.com>

pkg/analysis_server/test/protocol_server_test.dart

@@ -186,7 +186,7 @@ class AnalysisErrorTest {
       },
       MESSAGE: 'my message',
       CODE: 'my_lint',
-      URL: 'https://dart-lang.github.io/linter/lints/my_lint.html',
+      URL: 'https://dart.dev/lints/my_lint',
       HAS_FIX: false
     });
   }

pkg/analyzer/README.md

@@ -101,7 +101,7 @@ See the [LICENSE] file.
 [serverapi]: https://htmlpreview.github.io/?https://github.com/dart-lang/sdk/blob/main/pkg/analysis_server/doc/api.html
 [dart analyze]: https://dart.dev/tools/dart-analyze
 [list]: https://groups.google.com/a/dartlang.org/forum/#!forum/analyzer-discuss
-[lintrules]: https://dart-lang.github.io/linter/lints/
+[lintrules]: https://dart.dev/lints
 [glob]: https://pub.dev/packages/glob
 [LICENSE]: https://github.com/dart-lang/sdk/blob/main/pkg/analyzer/LICENSE
 [dart format]: https://github.com/dart-lang/dart_style

pkg/analyzer/lib/src/dart/error/lint_codes.dart

@@ -35,8 +35,7 @@ class LintCode extends ErrorCode {
   ErrorType get type => ErrorType.LINT;
 
   @override
-  String get url =>
-      _url ?? 'https://dart-lang.github.io/linter/lints/$name.html';
+  String get url => _url ?? 'https://dart.dev/lints/$name';
 
   @override
   bool operator ==(Object other) =>