require 3.4 SDK

.github/workflows/stream_transform.yaml

diff --git a/.github/workflows/stream_transform.yaml b/.github/workflows/stream_transform.yaml
index a36a776..38be5cc 100644
--- a/.github/workflows/stream_transform.yaml
+++ b/.github/workflows/stream_transform.yaml
@@ -59,7 +59,7 @@
         # Add macos-latest and/or windows-latest if relevant for this package.
         os: [ubuntu-latest]
         # Bump SDK for Legacy tests when changing min SDK.
-        sdk: [3.1, dev]
+        sdk: [3.4, dev]
     steps:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683
       - uses: dart-lang/setup-dart@e630b99d28a3b71860378cafdc2a067c71107f94

pkgs/stream_transform/CHANGELOG.md

diff --git a/pkgs/stream_transform/CHANGELOG.md b/pkgs/stream_transform/CHANGELOG.md
index 5c6a78d..b09778b 100644
--- a/pkgs/stream_transform/CHANGELOG.md
+++ b/pkgs/stream_transform/CHANGELOG.md
@@ -1,5 +1,7 @@
 ## 2.1.2-wip
 
+- Require Dart 3.4 or greater.
+
 ## 2.1.1
 
 - Require Dart 3.1 or greater

pkgs/stream_transform/pubspec.yaml

diff --git a/pkgs/stream_transform/pubspec.yaml b/pkgs/stream_transform/pubspec.yaml
index 725d746..91840b7 100644
--- a/pkgs/stream_transform/pubspec.yaml
+++ b/pkgs/stream_transform/pubspec.yaml
@@ -4,7 +4,7 @@
 repository: https://github.com/dart-lang/tools/tree/main/pkgs/stream_transform
 
 environment:
-  sdk: ^3.1.0
+  sdk: ^3.4.0
 
 dev_dependencies:
   async: ^2.5.0