update lock file

pubspec.lock

@@ -164,5 +164,5 @@ packages:
     source: hosted
     version: "2.1.0"
 sdks:
-  dart: ">=2.12.0-0.0 <3.0.0"
-  flutter: ">=1.22.0"
+  dart: ">=2.12.0 <3.0.0"
+  flutter: ">=2.0.0"