[native_assets_builder] v0.3.1 (#937)

diff --git a/pkgs/native_assets_builder/.pubignore b/pkgs/native_assets_builder/.pubignore
new file mode 100644
index 0000000..f5b87e0
--- /dev/null
+++ b/pkgs/native_assets_builder/.pubignore
@@ -0,0 +1,14 @@
+# Please keep consistent with .gitignore.
+
+# https://dart.dev/guides/libraries/private-files
+# Created by `dart pub`
+.dart_tool/
+
+# Avoid committing pubspec.lock for library packages; see
+# https://dart.dev/guides/libraries/private-files#pubspeclock.
+pubspec.lock
+
+coverage/
+
+# Additional pub ignores
+test_data/
diff --git a/pkgs/native_assets_builder/CHANGELOG.md b/pkgs/native_assets_builder/CHANGELOG.md
index 278f0d2..2477fd0 100644
--- a/pkgs/native_assets_builder/CHANGELOG.md
+++ b/pkgs/native_assets_builder/CHANGELOG.md
@@ -1,4 +1,4 @@
-## 0.3.1-wip
+## 0.3.1
 
 - Add support for `runPackageName` to avoid native assets for packages that
   the root package depends on but the package being run doesn't.
diff --git a/pkgs/native_assets_builder/pubspec.yaml b/pkgs/native_assets_builder/pubspec.yaml
index 02dd7f7..e785f97 100644
--- a/pkgs/native_assets_builder/pubspec.yaml
+++ b/pkgs/native_assets_builder/pubspec.yaml
@@ -1,7 +1,7 @@
 name: native_assets_builder
 description: >-
   This package is the backend that invokes top-level `build.dart` scripts.
-version: 0.3.1-wip
+version: 0.3.1
 repository: https://github.com/dart-lang/native/tree/main/pkgs/native_assets_builder
 
 environment: