Resync WPT shadow DOM tests.
Created attachment 427019 [details] Reimported tests
Created attachment 427020 [details] Added the missing expected result
Created attachment 427025 [details] Patch for landing
Created attachment 427026 [details] Patch for landing
Committed r276584 (237020@main): <https://commits.webkit.org/237020@main>
<rdar://problem/77144206>