Prep release for beta (#338)

PiperOrigin-RevId: 340722774

Co-authored-by: jakemac <jakemac@google.com>
diff --git a/CHANGELOG.md b/CHANGELOG.md
index b3fcf38..284b31e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,7 @@
+## 0.17.0-nullsafety.2
+
+* Update SDK constraints to >=2.12.0-0 <3.0.0 based on beta release guidelines.
+
 ## 0.17.0-nullsafety.1
 
 * Allow prereleases of the 2.12 Dart SDK.
diff --git a/pubspec.yaml b/pubspec.yaml
index ca12def..2d3d582 100644
--- a/pubspec.yaml
+++ b/pubspec.yaml
@@ -1,5 +1,5 @@
 name: intl
-version: 0.17.0-nullsafety.1
+version: 0.17.0-nullsafety.2
 homepage: https://github.com/dart-lang/intl
 description: >-
   Contains code to deal with internationalized/localized messages, date and
@@ -7,8 +7,7 @@
   internationalization issues.
 
 environment:
-  # This must remain a tight constraint until nnbd is stable
-  sdk: '>=2.11.0-180.0.dev <2.12.0'
+  sdk: '>=2.12.0-0 <3.0.0'
 
 dependencies:
   clock: ^1.1.0-nullsafety.1