update flutter sdk and libraries

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: '>=2.19.2 <3.0.0'
+  sdk: ^3.0.0
 
 # Dependencies specify other packages that your package needs in order to work.
 # To automatically upgrade your package dependencies to the latest versions
@@ -38,7 +38,7 @@ dependencies:
 
   path: ^1.8.2
   pdfx: ^2.3.0
-  permission_handler: ^10.2.0
+  permission_handler: ^11.4.0
   http: ^1.2.2
   path_provider: ^2.1.5
   flutter_cache_manager: ^3.4.1