remove serialization. it's moved to github

pkg/pkg.status

Index: pkg/pkg.status
diff --git a/pkg/pkg.status b/pkg/pkg.status
index 9b8dad1a3951da71818e77fb7efb4ac2b7ac5c4f..c56fbbe26c9dc3746c60b20b4bbc9c53530b65b4 100644
--- a/pkg/pkg.status
+++ b/pkg/pkg.status
@@ -383,11 +383,7 @@ watcher/test/directory_watcher/linux_test: Skip # Issue 16118
 # simulator.
 *: Skip
 
-# Skip serialization test that explicitly has no library declaration in the
-# test on Dartium, which requires all tests to have a library.
 [ $compiler == none && ( $runtime == dartium || $runtime == drt || $runtime == ContentShellOnAndroid) ]
-serialization/test/no_library_test: Skip # Expected Failure
-serialization/test/serialization_test: Fail # 13921
 unittest/test/async_exception_test: RuntimeError # 13921
 unittest/test/async_exception_with_future_test: RuntimeError # 13921
 unittest/test/async_setup_teardown_test: RuntimeError # 13921