Add a macOS WK1 baseline for imported/w3c/web-platform-tests/fullscreen/api/document-exit-fullscreen-nested-shadow-dom
Test gardening commit 257506@main (1f9e72a2795b): <https://commits.webkit.org/257506@main> Reviewed commits have been landed. Closing PR #7280 and removing active labels.
<rdar://problem/103099841>