Update SDK constraint in pubspec.yaml

Author: derekxu16

.github/workflows/dart.yml

@@ -7,7 +7,8 @@ repository: https://github.com/dart-lang/http/tree/master/pkgs/http_profile
 publish_to: none
 
 environment:
-  sdk: ^3.0.0
+  # TODO(derekxu16): Change the following constraint to ^3.4.0 before publishing this package.
+  sdk: ^3.4.0-149.0.dev
 
 dependencies:
   test: ^1.24.9