fix coverage

Author: felangel

bricks/dart_frog_prod_server/hooks/test/post_gen_test.dart

@@ -54,7 +54,6 @@ void main() {
       expect(
         ExitOverrides.runZoned(
           () => post_gen.run(_FakeHookContext(logger: logger)),
-          exit: (_) {},
         ),
         completes,
       );