[Gardening]: NEW TEST (271377@main): [ Sonoma ] http/wpt/webcodecs/en…

…coder-task-failing.html is constant failure

https://bugs.webkit.org/show_bug.cgi?id=265685
rdar://119043575

Unreviewed test gardening.

Adding test expectation

* LayoutTests/platform/mac/TestExpectations:

Canonical link: https://commits.webkit.org/271404@main

LayoutTests/platform/mac/TestExpectations

@@ -2612,3 +2612,5 @@ webkit.org/b/264607 [ Sonoma+ ] css1/box_properties/acid_test.html [ Pass Timeou
 # webkit.org/b/265536 ([ macOS ] 2 tests in inspector/layers are flaky failures)
 inspector/layers/layers-compositing-reasons.html [ Pass Failure ]
 inspector/layers/layers-blending-compositing-reasons.html [ Pass Failure ]
+
+webkit.org/b/265685 [ Sonoma+ ] http/wpt/webcodecs/encoder-task-failing.html [ Failure ]