Automatic update from web-platform-testsAdd a lint to catch adding files that would otherwise be ignored by git. wpt-commits: b3b4332e7aaf7b027c11be8a0750b9136bb90a70 wpt-pr: 9902 wpt-commits: b3b4332e7aaf7b027c11be8a0750b9136bb90a70 wpt-pr: 9902