[GARDENING] REGRESSION (281435@main): [ macOS ] 2x imported/w3c/web-platform-tests/css/css-writing-modes/ text-orientation-* is a flaky ImageOnlyFailure.

https://bugs.webkit.org/show_bug.cgi?id=278425
rdar://134375682

Unreviewed test gardening.

Setting test expectations.

* LayoutTests/platform/mac/TestExpectations:

Canonical link: https://commits.webkit.org/282539@main

Author: aviduya

LayoutTests/platform/mac/TestExpectations

@@ -2514,3 +2514,7 @@ imported/w3c/web-platform-tests/css/css-view-transitions/capture-with-opacity-ze
 
 # webkit.org/b/278318 [macOS Debug] ASSERTION FAILED: m_wrapper on media/video-playsinline.html, also flaky failure in Release
 [ Debug ] media/video-playsinline.html [ Pass Crash ]
+
+# webkit.org/b/278425 REGRESSION (281435@main): [ macOS ] 2x imported/w3c/web-platform-t ests/css/css-writing-modes/ text-orientation-* is a flaky ImageOnlyFailure. 
+imported/w3c/web-platform-tests/css/css-writing-modes/text-orientation-mixed-srl-016.xht [ Pass ImageOnlyFailure ]
+imported/w3c/web-platform-tests/css/css-writing-modes/text-orientation-upright-srl-018.xht [ Pass ImageOnlyFailure ]