Dont assume there has to be a main.dart for a flutter app/package

packages/melos/lib/src/package.dart

@@ -814,15 +814,14 @@ class Package {
   /// This is determined by ensuring all the following conditions are met:
   ///  a) the package depends on the Flutter SDK.
   ///  b) the package does not define itself as a Flutter plugin inside pubspec.yaml.
-  ///  c) a lib/main.dart file exists in the package.
   bool get isFlutterApp {
     // Must directly depend on the Flutter SDK.
     if (!isFlutterPackage) return false;
 
     // Must not have a Flutter plugin definition in it's pubspec.yaml.
     if (pubSpec.flutter?.plugin != null) return false;
 
-    return File(joinAll([path, 'lib', 'main.dart'])).existsSync();
+    return true;
   }
 
   bool get isAddToApp {