Skip http/tests/site-isolation/draw-after-navigation.html on iOS

https://bugs.webkit.org/show_bug.cgi?id=263371

Unreviewed.

Skip this test for now like we do the other test that draws pixels from site-isolated
iframes because the meta viewport size isn't hooked up right yet.  The test was always
failing on iOS.

* LayoutTests/platform/ios/TestExpectations:

Canonical link: https://commits.webkit.org/269515@main

LayoutTests/platform/ios/TestExpectations

@@ -4567,6 +4567,7 @@ imported/w3c/web-platform-tests/css/css-lists/content-property/marker-text-match
 
 http/tests/site-isolation/mouse-events/ [ Skip ]
 webkit.org/b/257904 http/tests/site-isolation/basic-iframe.html [ Skip ]
+webkit.org/b/257904 http/tests/site-isolation/draw-after-navigation.html [ Skip ]
 webkit.org/b/257904 http/tests/site-isolation/selection-focus.html [ Skip ]
 
 # This test can't be enabled on iOS until EventSenderProxyIOS::keyDown() is implemented.