Update the web platform tests for shadow DOM and declarative Shadow DOM implementation. In particular, enable streaming by default.
Pull request: https://github.com/WebKit/WebKit/pull/7537
Committed 257820@main (27b052173dc3): <https://commits.webkit.org/257820@main> Reviewed commits have been landed. Closing PR #7537 and removing active labels.
<rdar://problem/103329207>