downgrade dart sdk for HarmonyOS

Author: samu1oto

pubspec.lock

@@ -542,5 +542,5 @@ packages:
     source: hosted
     version: "0.0.6"
 sdks:
-  dart: ">=3.9.2 <4.0.0"
+  dart: ">=3.9.0 <4.0.0"
   flutter: ">=3.35.0"

pubspec.yaml

@@ -19,7 +19,7 @@ publish_to: 'none' # Remove this line if you wish to publish to pub.dev
 version: 1.0.0+1
 
 environment:
-  sdk: ^3.9.2
+  sdk: ^3.4.4
 
 # Dependencies specify other packages that your package needs in order to work.
 # To automatically upgrade your package dependencies to the latest versions