prepare v1.30.1 discontinue release (#5003)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index e39ccb9..e656581 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+# 1.30.1
+
+- Clearly mark discontinued in readme.
+
 # 1.30.0
 
 - new lint: `enable_null_safety`
diff --git a/README.md b/README.md
index 4b5a368..bddeafb 100644
--- a/README.md
+++ b/README.md
@@ -1,3 +1,7 @@
+# This package is discontinued.

+

+Please see the current source code at https://github.com/dart-lang/sdk/tree/main/pkg/linter

+

 # Linter for Dart

 

 The Dart Linter package defines lint rules that identify and report on "lints" found in Dart code.  Linting is performed by the Dart

diff --git a/pubspec.yaml b/pubspec.yaml
index 487cb49..e60a25e 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,12 +1,10 @@
 name: linter
-version: 1.30.0
+version: 1.30.1
 
 description: >-
-  The implementation of the lint rules supported by the analyzer framework.
-  This package is not intended to be used directly.
-homepage: https://github.com/dart-lang/linter
+  Discontinued. This package is not intended to be used directly.
+homepage: https://dart.dev/tools/linter-rules
 repository: https://github.com/dart-lang/linter
-documentation: https://dart-lang.github.io/linter/lints
 
 environment:
   sdk: '>=2.17.0 <3.0.0'