Update status for failing and flaky tests.

pkg/pkg.status

Index: pkg/pkg.status
diff --git a/pkg/pkg.status b/pkg/pkg.status
index 4ddace9b626d237833f41be9b6cba562940d666a..ff4c1c7bbf711d4dfde2f392370f0f522653fbd4 100644
--- a/pkg/pkg.status
+++ b/pkg/pkg.status
@@ -84,6 +84,7 @@ analyzer/test/generated/static_warning_code_test: Pass, Slow # Issue 21628
 analyzer/test/generated/strong_mode_test: Pass, Slow # Issue 21628
 analyzer/test/generated/type_system_test: Pass, Slow # Issue 21628
 analyzer/test/generated/utilities_test: Pass, Slow # Issue 21628
+analyzer/test/source/embedder_test: Skip # Issue 21628
 analyzer/test/source/package_map_provider_test: Skip # Issue 21628
 analyzer/test/src/context/cache_test: Pass, Slow # Issue 21628
 analyzer/test/src/context/context_test: Pass, Timeout # dartbug.com/23658
@@ -117,6 +118,7 @@ analyzer/test/src/task/options_test: Pass, Slow # Issue 21628
 analyzer/test/src/task/options_work_manager_test: Pass, Slow # Issue 21628
 analyzer/test/src/task/strong/checker_test: Pass, Slow # Issue 21628
 analyzer/test/src/task/strong/inferred_type_test: Pass, Slow # Issue 21628
+analyzer/test/src/task/strong_mode_test: Pass, Slow # Issue 21628
 analyzer/test/src/task/yaml_test: Pass, Slow # Issue 21628
 analyzer/tool/task_dependency_graph/check_test: Skip # Issue 21628
 collection/test/equality_test/01: Fail # Issue 1533