[Gardening]: REGRESSION (269641@main): [ Ventura+ arm64 ] inspector/u…

…nit-tests/iterableweakset.html is a flaky failure

https://bugs.webkit.org/show_bug.cgi?id=264426
rdar://118129008

Unreviewed test gardening.

Adding test expectation

* LayoutTests/platform/mac/TestExpectations:

Canonical link: https://commits.webkit.org/270400@main

LayoutTests/platform/mac/TestExpectations

@@ -2623,3 +2623,5 @@ webkit.org/b/264001 [ Debug ] imported/w3c/web-platform-tests/requestidlecallbac
 webkit.org/b/264177 requestidlecallback/requestidlecallback-deadline-shortened-by-rendering-update.html [ Pass Failure ]
 
 webkit.org/b/264349 http/tests/site-isolation/frame-access-after-window-open.html [ Timeout ]
+
+webkit.org/b/264426 [ Ventura+ arm64 ] inspector/unit-tests/iterableweakset.html [ Pass Failure ]