prepare to publish convert (#39)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index d920ec6..011af57 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,14 +1,7 @@
-## 2.2.0-nullsafety-dev
+## 3.0.0-nullsafety
 
 Pre-release for the null safety migration of this package.
 
-Note that 2.2.0 may not be the final stable null safety release version, we
-reserve the right to release it as a 3.0.0 breaking change.
-
-This release will be pinned to only allow pre-release sdk versions starting from
-2.10.0-2.0.dev, which is the first version where this package will appear in the
-null safety allow list.
-
  * Added `CodePage` class for single-byte `Encoding` implementations.
 
 ## 2.1.1
diff --git a/pubspec.yaml b/pubspec.yaml
index aad3ebe..d3cdea4 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: convert
-version: 2.2.0-nullsafety-dev
+version: 3.0.0-nullsafety
 description: Utilities for converting between data representations.
 repository: https://github.com/dart-lang/convert
 
@@ -13,3 +13,11 @@
   charcode: ^1.2.0-nullsafety.3
   pedantic: ^1.10.0-nullsafety.3
   test: ^1.16.0-nullsafety.9
+
+# Because these packages depend on the pre-v3 version of this package
+dependency_overrides:
+  analyzer: 0.40.6
+  crypto: 2.1.5
+  shelf_static: 0.2.8
+  test: 1.16.0-nullsafety.9
+  web_socket_channel: 1.1.0